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Skinny triangle

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1608:. However, this distance is still short compared to the distance to the object being measured (the height of the triangle) and the skinny triangle solution can be applied and still achieve great accuracy. The alternative method of measuring the base angles is theoretically possible but not so accurate. The base angles are very nearly right angles and would need to be measured with much greater precision than the parallax angle in order to get the same accuracy. 20: 1080: 903: 1611:
The same method of measuring parallax angles and applying the skinny triangle can be used to measure the distances to stars, at least the nearer ones. In the case of stars, however, a longer baseline than the diameter of the Earth is usually required. Instead of using two stations on the baseline,
1725:, relies on making estimates of wind speeds aloft over long distances to calculate a desired heading. Since predicted or reported wind speeds are rarely accurate, corrections to the aircraft's heading need to be made at regular intervals. Skinny triangles form the basis of the 689: 807: 1069: 547: 603: 1678:
in the sight corresponds to a range of 1000 metres. There is an inverse relationship between the angle measured in a sniper's sight and the distance to target. For instance, if this same target measures
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Applications of the skinny triangle occur in any situation where the distance to a far object is to be determined. This can occur in surveying, astronomy, and also has military applications.
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The skinny triangle is useful in gunnery in that it allows a relationship to be calculated between the range and size of the target without the shooter needing to compute or look up any
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angle formed by the object as seen by the two stations. This baseline is usually very long for best accuracy; in principle the stations could be on opposite sides of the
614: 733: 1636:. There is an inverse relationship between the distance in parsecs and the angle in arcseconds. For instance, two arcseconds corresponds to a distance of 849:
represents the base angle of the triangle and is this value because the sum of the internal angles of any triangle (in this case the two base angles plus
1729:, which is "After travelling 60 miles, your heading is one degree off for every mile you're off course". "60" is very close to 180 / π = 57.30. 1612:
two measurements are made from the same station at different times of year. During the intervening period, the orbit of the Earth around the
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This result is equivalent to assuming that the length of the base of the triangle is equal to the length of the arc of circle of radius
1025: 503: 562: 1713:. Or, perhaps more usefully, a target 6 feet in height and measuring 4 MOA corresponds to a range of 1800 yards (just over a mile). 1957: 1938: 1917: 1892: 1871: 1484: 966: 859: 939:. The error is 10% or less for angles less than about 43°, and improves quadratically: when the angle decreases by a factor of 815: 1982: 1616:
moves the measuring station a great distance, so providing a very long baseline. This baseline can be as long as the
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objects. The base of the triangle is formed by the distance between two measuring stations and the angle
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as they are with milliradians; however, there is a convenient approximate whole number correspondence in
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The proof of the skinny triangle solution follows from the small-angle approximation by applying the
684:{\displaystyle \cos \theta =\sin \left({\frac {\pi }{2}}-\theta \right)\approx 1,\quad \theta \ll 1} 71: 802:{\displaystyle {\frac {b}{\sin \theta }}={\frac {r}{\sin \left({\frac {\pi -\theta }{2}}\right)}}} 853:) are equal to π. Applying the small angle approximations to the law of sines above results in 1953: 1934: 1913: 1888: 1867: 1621: 297: 1902:
Holbrow, Charles H.; Lloyd, James N.; Amato, Joseph C.; Galvez, Enrique; Parks, Beth (2010).
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The approximated solution to the skinny isosceles triangle, referring to figure 1, is:
63: 1079: 1971: 1691: 1687: 1726: 1690:(MOA). The distances corresponding to minutes of arc are not exact numbers in the 1593: 1443:
The approximated solution to the right skinny triangle, referring to figure 3, is:
724: 31: 1928: 1903: 1861: 1667: 1663: 46:
of such triangles can be greatly simplified by using the approximation that the
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The skinny triangle is frequently used in astronomy to measure the distance to
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The error of this approximation is less than 10% for angles 31° or less.
953: 58:. The solution is particularly simple for skinny triangles that are also 39: 1659: 77:
The skinny triangle finds uses in surveying, astronomy, and shooting.
1629: 717: 55: 1605: 1078: 901: 51: 1064:{\displaystyle {\text{area}}\approx {\frac {1}{2}}\theta r^{2}\,} 542:{\displaystyle {\text{area}}\approx {\frac {1}{2}}\theta r^{2}\,} 1710: 1701: 1624:(AU). The distance to a star with a parallax angle of only one 957: 598:{\displaystyle \sin \theta \approx \theta ,\quad \theta \ll 1\,} 47: 1860:
Abell, George Ogden; Morrison, David; Wolff, Sidney C. (1987).
1613: 1519:{\displaystyle \tan \theta \approx \theta ,\quad \theta \ll 1} 1640:
and 0.5 arcsecond corresponds to a distance of two parsecs.
1009:{\displaystyle {\text{area}}={\frac {\sin \theta }{2}}r^{2}} 889:{\displaystyle {\frac {b}{\theta }}\approx {\frac {r}{1}}} 1686:
Another unit which is sometimes used on gunsights is the
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measured on a baseline of one AU is a unit known as the
1792: 1658:. Military and hunting telescopic sights often have a 1839: 1837: 1760: 1758: 842:{\displaystyle \scriptstyle {\frac {\pi -\theta }{2}}} 819: 701: 1538: 1487: 1452: 1028: 969: 862: 818: 736: 700: 617: 565: 506: 473: 1019:Applying the small angle approximations results in 1828: 1816: 1804: 1776: 1562: 1518: 1467: 1091:Table of tangent small-angle approximation errors 1063: 1008: 888: 841: 801: 708: 683: 597: 541: 489: 42:whose height is much greater than its base. The 1529:which when substituted into the exact solution 1478:This is based on the small-angle approximation 86:Table of sine small-angle approximation errors 1632:(pc) in astronomy and is equal to about 3.26 8: 1709:in the sight corresponds to a range of 100 1683:in the sight then the range is 500 metres. 1620:of the Earth's orbit or, equivalently, two 1780: 1950:Firearms, the law and forensic ballistics 1537: 1486: 1451: 1060: 1054: 1037: 1029: 1027: 1000: 978: 970: 968: 876: 863: 861: 820: 817: 774: 758: 737: 735: 699: 641: 616: 594: 564: 538: 532: 515: 507: 505: 486: 472: 1744:Infinitesimal oscillations of a pendulum 1272: 1104: 1089: 278: 99: 84: 18: 1754: 1843: 1721:A simple form of aviation navigation, 1666:, in this context usually called just 1910:Springer Science & Business Media 1764: 7: 709:{\displaystyle \scriptstyle \theta } 490:{\displaystyle b\approx r\theta \,} 1829:Abell, Morrison & Wolff (1987) 1817:Abell, Morrison & Wolff (1987) 1805:Abell, Morrison & Wolff (1987) 1777:Abell, Morrison & Wolff (1987) 14: 1563:{\displaystyle b=h\tan \theta \ } 1468:{\displaystyle b\approx h\theta } 74:can be entirely dispensed with. 1506: 727:. Again referring to figure 1: 671: 584: 1930:Basics of Photonics and Optics 66:: in these cases the need for 1: 899:which is the desired result. 1905:Modern Introductory Physics 1863:Exploration of the Universe 1831:, p. 414–416, 418–419. 1573:yields the desired result. 1999: 1884:Physics for Advanced Level 1647: 554:small-angle approximations 54:is equal to that angle in 1739:Small angle approximation 1275: 1107: 1086:The right skinny triangle 943:, the error decreases by 281: 102: 26:Isosceles skinny triangle 1952:. Taylor & Francis. 1881:Breithaupt, Jim (2000). 1866:. Saunders College Pub. 1705:in height and measuring 1674:in height and measuring 1948:Warlow, Tom A. (1996). 1933:. Trafford Publishing. 1670:or mil-dots. A target 1656:trigonometric functions 1650:Telemeter (rangefinder) 954:side-angle-side formula 68:trigonometric functions 1564: 1520: 1469: 1087: 1065: 1010: 928: 890: 843: 803: 710: 685: 599: 543: 491: 27: 1927:Vasan, Srini (2004). 1819:, Inside front cover. 1793:Holbrow et al. (2010) 1565: 1521: 1470: 1082: 1066: 1011: 916:approaches length of 905: 891: 844: 804: 711: 686: 600: 552:This is based on the 544: 492: 22: 1779:, pp. 414–415; 1536: 1485: 1450: 1026: 967: 860: 816: 734: 698: 615: 563: 504: 471: 1092: 960:of the triangle is 935:subtended by angle 87: 1983:Types of triangles 1887:. Nelson Thornes. 1622:astronomical units 1560: 1516: 1465: 1090: 1088: 1061: 1006: 929: 886: 839: 838: 799: 706: 705: 681: 595: 539: 487: 85: 81:Isosceles triangle 28: 1795:, pp. 30–31. 1781:Breithaupt (2000) 1559: 1441: 1440: 1437: 1436: 1269: 1268: 1045: 1032: 994: 973: 884: 871: 836: 797: 790: 753: 649: 523: 510: 462: 461: 458: 457: 275: 274: 1990: 1963: 1944: 1923: 1898: 1877: 1847: 1841: 1832: 1826: 1820: 1814: 1808: 1802: 1796: 1790: 1784: 1774: 1768: 1762: 1708: 1704: 1682: 1677: 1673: 1639: 1569: 1567: 1566: 1561: 1557: 1525: 1523: 1522: 1517: 1474: 1472: 1471: 1466: 1273: 1105: 1093: 1070: 1068: 1067: 1062: 1059: 1058: 1046: 1038: 1033: 1030: 1015: 1013: 1012: 1007: 1005: 1004: 995: 990: 979: 974: 971: 948: 942: 895: 893: 892: 887: 885: 877: 872: 864: 848: 846: 845: 840: 837: 832: 821: 808: 806: 805: 800: 798: 796: 795: 791: 786: 775: 759: 754: 752: 738: 715: 713: 712: 707: 690: 688: 687: 682: 661: 657: 650: 642: 604: 602: 601: 596: 548: 546: 545: 540: 537: 536: 524: 516: 511: 508: 496: 494: 493: 488: 279: 100: 88: 16:Type of triangle 1998: 1997: 1993: 1992: 1991: 1989: 1988: 1987: 1968: 1967: 1966: 1960: 1947: 1941: 1926: 1920: 1901: 1895: 1880: 1874: 1859: 1855: 1850: 1842: 1835: 1827: 1823: 1815: 1811: 1803: 1799: 1791: 1787: 1775: 1771: 1763: 1756: 1752: 1735: 1719: 1706: 1699: 1680: 1675: 1671: 1652: 1646: 1637: 1590: 1582: 1534: 1533: 1483: 1482: 1448: 1447: 1077: 1050: 1024: 1023: 996: 980: 965: 964: 944: 940: 858: 857: 822: 814: 813: 776: 770: 763: 742: 732: 731: 696: 695: 640: 636: 613: 612: 561: 560: 528: 502: 501: 469: 468: 83: 64:right triangles 36:skinny triangle 17: 12: 11: 5: 1996: 1994: 1986: 1985: 1980: 1970: 1969: 1965: 1964: 1958: 1945: 1939: 1924: 1918: 1899: 1893: 1878: 1872: 1856: 1854: 1851: 1849: 1848: 1833: 1821: 1809: 1807:, p. 414. 1797: 1785: 1769: 1767:, p. 124. 1753: 1751: 1748: 1747: 1746: 1741: 1734: 1731: 1723:dead reckoning 1718: 1715: 1696:imperial units 1662:calibrated in 1645: 1642: 1589: 1586: 1581: 1578: 1571: 1570: 1556: 1553: 1550: 1547: 1544: 1541: 1527: 1526: 1515: 1512: 1509: 1505: 1502: 1499: 1496: 1493: 1490: 1476: 1475: 1464: 1461: 1458: 1455: 1439: 1438: 1435: 1434: 1431: 1428: 1424: 1423: 1420: 1417: 1413: 1412: 1409: 1406: 1402: 1401: 1398: 1395: 1391: 1390: 1387: 1384: 1380: 1379: 1376: 1373: 1369: 1368: 1365: 1362: 1358: 1357: 1354: 1351: 1347: 1346: 1343: 1340: 1336: 1335: 1332: 1329: 1325: 1324: 1321: 1318: 1314: 1313: 1310: 1307: 1303: 1302: 1299: 1296: 1292: 1291: 1288: 1285: 1281: 1280: 1277: 1270: 1267: 1266: 1263: 1260: 1256: 1255: 1252: 1249: 1245: 1244: 1241: 1238: 1234: 1233: 1230: 1227: 1223: 1222: 1219: 1216: 1212: 1211: 1208: 1205: 1201: 1200: 1197: 1194: 1190: 1189: 1186: 1183: 1179: 1178: 1175: 1172: 1168: 1167: 1164: 1161: 1157: 1156: 1153: 1150: 1146: 1145: 1142: 1139: 1135: 1134: 1131: 1128: 1124: 1123: 1120: 1117: 1113: 1112: 1109: 1101: 1100: 1097: 1076: 1075:Right triangle 1073: 1072: 1071: 1057: 1053: 1049: 1044: 1041: 1036: 1017: 1016: 1003: 999: 993: 989: 986: 983: 977: 897: 896: 883: 880: 875: 870: 867: 835: 831: 828: 825: 810: 809: 794: 789: 785: 782: 779: 773: 769: 766: 762: 757: 751: 748: 745: 741: 704: 692: 691: 680: 677: 674: 670: 667: 664: 660: 656: 653: 648: 645: 639: 635: 632: 629: 626: 623: 620: 606: 605: 593: 590: 587: 583: 580: 577: 574: 571: 568: 550: 549: 535: 531: 527: 522: 519: 514: 498: 497: 485: 482: 479: 476: 460: 459: 456: 455: 452: 449: 445: 444: 441: 438: 434: 433: 430: 427: 423: 422: 419: 416: 412: 411: 408: 405: 401: 400: 397: 394: 390: 389: 386: 383: 379: 378: 375: 372: 368: 367: 364: 361: 357: 356: 353: 350: 346: 345: 342: 339: 335: 334: 331: 328: 324: 323: 320: 317: 313: 312: 309: 306: 302: 301: 294: 291: 287: 286: 283: 276: 273: 272: 269: 266: 262: 261: 258: 255: 251: 250: 247: 244: 240: 239: 236: 233: 229: 228: 225: 222: 218: 217: 214: 211: 207: 206: 203: 200: 196: 195: 192: 189: 185: 184: 181: 178: 174: 173: 170: 167: 163: 162: 159: 156: 152: 151: 148: 145: 141: 140: 137: 134: 130: 129: 126: 123: 119: 118: 115: 112: 108: 107: 104: 96: 95: 92: 82: 79: 15: 13: 10: 9: 6: 4: 3: 2: 1995: 1984: 1981: 1979: 1976: 1975: 1973: 1961: 1959:0-7484-0432-5 1955: 1951: 1946: 1942: 1940:1-4120-4138-4 1936: 1932: 1931: 1925: 1921: 1919:0-387-79079-9 1915: 1911: 1907: 1906: 1900: 1896: 1894:0-7487-4315-4 1890: 1886: 1885: 1879: 1875: 1873:0-03-005143-6 1869: 1865: 1864: 1858: 1857: 1852: 1846:, p. 87. 1845: 1844:Warlow (1996) 1840: 1838: 1834: 1830: 1825: 1822: 1818: 1813: 1810: 1806: 1801: 1798: 1794: 1789: 1786: 1783:, p. 26. 1782: 1778: 1773: 1770: 1766: 1761: 1759: 1755: 1749: 1745: 1742: 1740: 1737: 1736: 1732: 1730: 1728: 1724: 1716: 1714: 1712: 1703: 1697: 1693: 1692:metric system 1689: 1688:minute of arc 1684: 1669: 1665: 1661: 1657: 1651: 1643: 1641: 1635: 1631: 1627: 1623: 1619: 1615: 1609: 1607: 1603: 1599: 1595: 1587: 1585: 1579: 1577: 1574: 1554: 1551: 1548: 1545: 1542: 1539: 1532: 1531: 1530: 1513: 1510: 1507: 1503: 1500: 1497: 1494: 1491: 1488: 1481: 1480: 1479: 1462: 1459: 1456: 1453: 1446: 1445: 1444: 1432: 1429: 1426: 1425: 1421: 1418: 1415: 1414: 1410: 1407: 1404: 1403: 1399: 1396: 1393: 1392: 1388: 1385: 1382: 1381: 1377: 1374: 1371: 1370: 1366: 1363: 1360: 1359: 1355: 1352: 1349: 1348: 1344: 1341: 1338: 1337: 1333: 1330: 1327: 1326: 1322: 1319: 1316: 1315: 1311: 1308: 1305: 1304: 1300: 1297: 1294: 1293: 1289: 1286: 1283: 1282: 1278: 1274: 1271: 1264: 1261: 1258: 1257: 1253: 1250: 1247: 1246: 1242: 1239: 1236: 1235: 1231: 1228: 1225: 1224: 1220: 1217: 1214: 1213: 1209: 1206: 1203: 1202: 1198: 1195: 1192: 1191: 1187: 1184: 1181: 1180: 1176: 1173: 1170: 1169: 1165: 1162: 1159: 1158: 1154: 1151: 1148: 1147: 1143: 1140: 1137: 1136: 1132: 1129: 1126: 1125: 1121: 1118: 1115: 1114: 1110: 1106: 1103: 1102: 1099:Small angles 1098: 1095: 1094: 1085: 1081: 1074: 1055: 1051: 1047: 1042: 1039: 1034: 1022: 1021: 1020: 1001: 997: 991: 987: 984: 981: 975: 963: 962: 961: 959: 955: 950: 947: 938: 934: 926: 922: 919: 915: 912: 908: 904: 900: 881: 878: 873: 868: 865: 856: 855: 854: 852: 833: 829: 826: 823: 792: 787: 783: 780: 777: 771: 767: 764: 760: 755: 749: 746: 743: 739: 730: 729: 728: 726: 721: 719: 702: 678: 675: 672: 668: 665: 662: 658: 654: 651: 646: 643: 637: 633: 630: 627: 624: 621: 618: 611: 610: 609: 591: 588: 585: 581: 578: 575: 572: 569: 566: 559: 558: 557: 555: 533: 529: 525: 520: 517: 512: 500: 499: 483: 480: 477: 474: 467: 466: 465: 453: 450: 447: 446: 442: 439: 436: 435: 431: 428: 425: 424: 420: 417: 414: 413: 409: 406: 403: 402: 398: 395: 392: 391: 387: 384: 381: 380: 376: 373: 370: 369: 365: 362: 359: 358: 354: 351: 348: 347: 343: 340: 337: 336: 332: 329: 326: 325: 321: 318: 315: 314: 310: 307: 304: 303: 299: 295: 292: 289: 288: 284: 280: 277: 270: 267: 264: 263: 259: 256: 253: 252: 248: 245: 242: 241: 237: 234: 231: 230: 226: 223: 220: 219: 215: 212: 209: 208: 204: 201: 198: 197: 193: 190: 187: 186: 182: 179: 176: 175: 171: 168: 165: 164: 160: 157: 154: 153: 149: 146: 143: 142: 138: 135: 132: 131: 127: 124: 121: 120: 116: 113: 110: 109: 105: 101: 98: 97: 94:Small angles 93: 90: 89: 80: 78: 75: 73: 69: 65: 61: 57: 53: 49: 45: 41: 37: 33: 25: 21: 1978:Trigonometry 1949: 1929: 1904: 1883: 1862: 1853:Bibliography 1824: 1812: 1800: 1788: 1772: 1765:Vasan (2004) 1727:1 in 60 rule 1720: 1698:. A target 1685: 1664:milliradians 1653: 1610: 1597: 1594:Solar System 1591: 1583: 1580:Applications 1575: 1572: 1528: 1477: 1442: 1096:Large angles 1083: 1018: 951: 945: 936: 932: 930: 924: 920: 913: 906: 898: 850: 811: 725:law of sines 722: 693: 607: 551: 463: 91:Large angles 76: 35: 32:trigonometry 29: 23: 1634:light years 50:of a small 1972:Categories 1750:References 1648:See also: 1618:major axis 909:Length of 1626:arcsecond 1588:Astronomy 1555:θ 1552:⁡ 1511:≪ 1508:θ 1501:θ 1498:≈ 1495:θ 1492:⁡ 1463:θ 1457:≈ 1287:(radians) 1284:(minutes) 1119:(radians) 1116:(degrees) 1048:θ 1035:≈ 988:θ 985:⁡ 927:decreases 923:as angle 874:≈ 869:θ 830:θ 827:− 824:π 812:The term 784:θ 781:− 778:π 768:⁡ 750:θ 747:⁡ 703:θ 676:≪ 673:θ 663:≈ 655:θ 652:− 644:π 634:⁡ 625:θ 622:⁡ 589:≪ 586:θ 579:θ 576:≈ 573:θ 570:⁡ 526:θ 513:≈ 484:θ 478:≈ 293:(radians) 290:(minutes) 114:(radians) 111:(degrees) 60:isosceles 1733:See also 1717:Aviation 1602:parallax 1433:−101.54 956:for the 44:solution 40:triangle 1672:1 metre 1660:reticle 1644:Gunnery 1600:is the 1422:−85.32 1411:−70.51 1400:−57.12 1389:−45.13 1378:−34.55 1367:−25.38 1356:−17.63 1345:−11.28 1265:−39.54 1254:−32.78 1243:−26.77 1232:−21.46 1221:−16.80 1210:−12.76 718:radians 56:radians 1956:  1937:  1916:  1891:  1870:  1681:2 mils 1638:0.5 pc 1630:parsec 1558:  1430:0.0175 1419:0.0160 1408:0.0145 1397:0.0131 1386:0.0116 1375:0.0102 1364:0.0087 1353:0.0073 1342:0.0058 1334:−6.35 1331:0.0044 1323:−2.82 1320:0.0029 1312:−0.71 1309:0.0015 1301:−0.03 1298:0.0003 1290:(ppm) 1279:error 1199:−9.31 1188:−6.43 1177:−4.09 1166:−2.30 1155:−1.02 1144:−0.25 1133:−0.01 1111:error 716:is in 454:50.77 451:0.0175 443:42.66 440:0.0160 432:35.26 429:0.0145 421:28.56 418:0.0131 410:22.56 407:0.0116 399:17.28 396:0.0102 388:12.69 385:0.0087 374:0.0073 363:0.0058 352:0.0044 341:0.0029 330:0.0015 319:0.0006 308:0.0003 285:error 271:20.92 260:17.19 249:13.92 238:11.07 128:0.005 106:error 72:tables 24:Fig. 1 1711:yards 1707:1 MOA 1676:1 mil 1606:Earth 1276:angle 1262:1.047 1251:0.960 1240:0.873 1229:0.785 1218:0.698 1207:0.611 1196:0.524 1185:0.436 1174:0.349 1163:0.262 1152:0.175 1141:0.087 1130:0.017 1108:angle 1084:Fig.3 918:chord 907:Fig.2 694:when 377:8.81 366:5.64 355:3.17 344:1.41 333:0.35 322:0.06 311:0.01 282:angle 268:1.047 257:0.960 246:0.873 235:0.785 227:8.61 224:0.698 216:6.50 213:0.611 205:4.72 202:0.524 194:3.25 191:0.436 183:2.06 180:0.349 172:1.15 169:0.262 161:0.51 158:0.175 150:0.13 147:0.087 139:0.02 136:0.035 125:0.017 103:angle 52:angle 38:is a 1954:ISBN 1935:ISBN 1914:ISBN 1889:ISBN 1868:ISBN 1702:inch 1668:mils 1122:(%) 1031:area 972:area 958:area 952:The 608:and 509:area 117:(%) 48:sine 34:, a 1614:Sun 1549:tan 1489:tan 982:sin 911:arc 765:sin 744:sin 631:sin 619:cos 567:sin 298:ppm 70:or 62:or 30:In 1974:: 1912:. 1908:. 1836:^ 1757:^ 1700:1 1427:60 1416:55 1405:50 1394:45 1383:40 1372:35 1361:30 1350:25 1339:20 1328:15 1317:10 1259:60 1248:55 1237:50 1226:45 1215:40 1204:35 1193:30 1182:25 1171:20 1160:15 1149:10 949:. 720:. 556:: 448:60 437:55 426:50 415:45 404:40 393:35 382:30 371:25 360:20 349:15 338:10 300:) 265:60 254:55 243:50 232:45 221:40 210:35 199:30 188:25 177:20 166:15 155:10 1962:. 1943:. 1922:. 1897:. 1876:. 1598:θ 1546:h 1543:= 1540:b 1514:1 1504:, 1460:h 1454:b 1306:5 1295:1 1138:5 1127:1 1056:2 1052:r 1043:2 1040:1 1002:2 998:r 992:2 976:= 946:k 941:k 937:θ 933:r 925:θ 921:b 914:l 882:1 879:r 866:b 851:θ 834:2 793:) 788:2 772:( 761:r 756:= 740:b 679:1 669:, 666:1 659:) 647:2 638:( 628:= 592:1 582:, 534:2 530:r 521:2 518:1 481:r 475:b 327:5 316:2 305:1 296:( 144:5 133:2 122:1

Index


trigonometry
triangle
solution
sine
angle
radians
isosceles
right triangles
trigonometric functions
tables
ppm
small-angle approximations
radians
law of sines

arc
chord
side-angle-side formula
area

Solar System
parallax
Earth
Sun
major axis
astronomical units
arcsecond
parsec
light years

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