REFERENCE
三角関数・√ 早見表
測量士補試験は電卓を使用できません。方向角・座標計算や写真縮尺の計算では、
問題冊子に与えられた三角関数・平方根の値を使います。学習・演習の確認用に早見表をまとめました。
📐 使い方のポイント
- 本試験では必要な sin・cos・tan・√ の値は問題文か、問題集の巻末の関数表で与えられます。暗記は不要です。
- この表は「与えられた値をどう当てはめるか」を練習で確認するためのものです。
- 座標計算では ΔX = S·cos(方向角)、ΔY = S·sin(方向角) のように使います。
- 写真測量では縮尺分母 m = H/f、√ は誤差計算(√n 倍の法則など)で登場します。
🎯 覚えておくと速い代表値
- sin30° = 0.5000 / cos30° = 0.8660 / tan30° ≒ 0.5774
- sin45° = cos45° = 0.7071 / tan45° = 1.0000
- sin60° = 0.8660 / cos60° = 0.5000 / tan60° ≒ 1.7321
- √2 ≒ 1.4142 / √3 ≒ 1.7321 / √5 ≒ 2.2361 / √10 ≒ 3.1623
📊 三角関数表 (0°〜90°)
| 角度 | sin | cos | tan |
| 0° | 0.0000 | 1.0000 | 0.0000 |
| 1° | 0.0175 | 0.9998 | 0.0175 |
| 2° | 0.0349 | 0.9994 | 0.0349 |
| 3° | 0.0523 | 0.9986 | 0.0524 |
| 4° | 0.0698 | 0.9976 | 0.0699 |
| 5° | 0.0872 | 0.9962 | 0.0875 |
| 6° | 0.1045 | 0.9945 | 0.1051 |
| 7° | 0.1219 | 0.9925 | 0.1228 |
| 8° | 0.1392 | 0.9903 | 0.1405 |
| 9° | 0.1564 | 0.9877 | 0.1584 |
| 10° | 0.1736 | 0.9848 | 0.1763 |
| 11° | 0.1908 | 0.9816 | 0.1944 |
| 12° | 0.2079 | 0.9781 | 0.2126 |
| 13° | 0.2250 | 0.9744 | 0.2309 |
| 14° | 0.2419 | 0.9703 | 0.2493 |
| 15° | 0.2588 | 0.9659 | 0.2679 |
| 16° | 0.2756 | 0.9613 | 0.2867 |
| 17° | 0.2924 | 0.9563 | 0.3057 |
| 18° | 0.3090 | 0.9511 | 0.3249 |
| 19° | 0.3256 | 0.9455 | 0.3443 |
| 20° | 0.3420 | 0.9397 | 0.3640 |
| 21° | 0.3584 | 0.9336 | 0.3839 |
| 22° | 0.3746 | 0.9272 | 0.4040 |
| 23° | 0.3907 | 0.9205 | 0.4245 |
| 24° | 0.4067 | 0.9135 | 0.4452 |
| 25° | 0.4226 | 0.9063 | 0.4663 |
| 26° | 0.4384 | 0.8988 | 0.4877 |
| 27° | 0.4540 | 0.8910 | 0.5095 |
| 28° | 0.4695 | 0.8829 | 0.5317 |
| 29° | 0.4848 | 0.8746 | 0.5543 |
| 30° | 0.5000 | 0.8660 | 0.5774 |
| 31° | 0.5150 | 0.8572 | 0.6009 |
| 32° | 0.5299 | 0.8480 | 0.6249 |
| 33° | 0.5446 | 0.8387 | 0.6494 |
| 34° | 0.5592 | 0.8290 | 0.6745 |
| 35° | 0.5736 | 0.8192 | 0.7002 |
| 36° | 0.5878 | 0.8090 | 0.7265 |
| 37° | 0.6018 | 0.7986 | 0.7536 |
| 38° | 0.6157 | 0.7880 | 0.7813 |
| 39° | 0.6293 | 0.7771 | 0.8098 |
| 40° | 0.6428 | 0.7660 | 0.8391 |
| 41° | 0.6561 | 0.7547 | 0.8693 |
| 42° | 0.6691 | 0.7431 | 0.9004 |
| 43° | 0.6820 | 0.7314 | 0.9325 |
| 44° | 0.6947 | 0.7193 | 0.9657 |
| 45° | 0.7071 | 0.7071 | 1.0000 |
| 46° | 0.7193 | 0.6947 | 1.0355 |
| 47° | 0.7314 | 0.6820 | 1.0724 |
| 48° | 0.7431 | 0.6691 | 1.1106 |
| 49° | 0.7547 | 0.6561 | 1.1504 |
| 50° | 0.7660 | 0.6428 | 1.1918 |
| 51° | 0.7771 | 0.6293 | 1.2349 |
| 52° | 0.7880 | 0.6157 | 1.2799 |
| 53° | 0.7986 | 0.6018 | 1.3270 |
| 54° | 0.8090 | 0.5878 | 1.3764 |
| 55° | 0.8192 | 0.5736 | 1.4281 |
| 56° | 0.8290 | 0.5592 | 1.4826 |
| 57° | 0.8387 | 0.5446 | 1.5399 |
| 58° | 0.8480 | 0.5299 | 1.6003 |
| 59° | 0.8572 | 0.5150 | 1.6643 |
| 60° | 0.8660 | 0.5000 | 1.7321 |
| 61° | 0.8746 | 0.4848 | 1.8040 |
| 62° | 0.8829 | 0.4695 | 1.8807 |
| 63° | 0.8910 | 0.4540 | 1.9626 |
| 64° | 0.8988 | 0.4384 | 2.0503 |
| 65° | 0.9063 | 0.4226 | 2.1445 |
| 66° | 0.9135 | 0.4067 | 2.2460 |
| 67° | 0.9205 | 0.3907 | 2.3559 |
| 68° | 0.9272 | 0.3746 | 2.4751 |
| 69° | 0.9336 | 0.3584 | 2.6051 |
| 70° | 0.9397 | 0.3420 | 2.7475 |
| 71° | 0.9455 | 0.3256 | 2.9042 |
| 72° | 0.9511 | 0.3090 | 3.0777 |
| 73° | 0.9563 | 0.2924 | 3.2709 |
| 74° | 0.9613 | 0.2756 | 3.4874 |
| 75° | 0.9659 | 0.2588 | 3.7321 |
| 76° | 0.9703 | 0.2419 | 4.0108 |
| 77° | 0.9744 | 0.2250 | 4.3315 |
| 78° | 0.9781 | 0.2079 | 4.7046 |
| 79° | 0.9816 | 0.1908 | 5.1446 |
| 80° | 0.9848 | 0.1736 | 5.6713 |
| 81° | 0.9877 | 0.1564 | 6.3138 |
| 82° | 0.9903 | 0.1392 | 7.1154 |
| 83° | 0.9925 | 0.1219 | 8.1443 |
| 84° | 0.9945 | 0.1045 | 9.5144 |
| 85° | 0.9962 | 0.0872 | 11.4301 |
| 86° | 0.9976 | 0.0698 | 14.3007 |
| 87° | 0.9986 | 0.0523 | 19.0811 |
| 88° | 0.9994 | 0.0349 | 28.6363 |
| 89° | 0.9998 | 0.0175 | 57.2900 |
| 90° | 1.0000 | 0.0000 | — |
📊 平方根表 (√1〜√100)
| n | √n |
| 1 | 1.0000 |
| 2 | 1.4142 |
| 3 | 1.7321 |
| 4 | 2.0000 |
| 5 | 2.2361 |
| 6 | 2.4495 |
| 7 | 2.6458 |
| 8 | 2.8284 |
| 9 | 3.0000 |
| 10 | 3.1623 |
| 11 | 3.3166 |
| 12 | 3.4641 |
| 13 | 3.6056 |
| 14 | 3.7417 |
| 15 | 3.8730 |
| 16 | 4.0000 |
| 17 | 4.1231 |
| 18 | 4.2426 |
| 19 | 4.3589 |
| 20 | 4.4721 |
| 21 | 4.5826 |
| 22 | 4.6904 |
| 23 | 4.7958 |
| 24 | 4.8990 |
| 25 | 5.0000 |
| 26 | 5.0990 |
| 27 | 5.1962 |
| 28 | 5.2915 |
| 29 | 5.3852 |
| 30 | 5.4772 |
| 31 | 5.5678 |
| 32 | 5.6569 |
| 33 | 5.7446 |
| 34 | 5.8310 |
| 35 | 5.9161 |
| 36 | 6.0000 |
| 37 | 6.0828 |
| 38 | 6.1644 |
| 39 | 6.2450 |
| 40 | 6.3246 |
| 41 | 6.4031 |
| 42 | 6.4807 |
| 43 | 6.5574 |
| 44 | 6.6332 |
| 45 | 6.7082 |
| 46 | 6.7823 |
| 47 | 6.8557 |
| 48 | 6.9282 |
| 49 | 7.0000 |
| 50 | 7.0711 |
| 51 | 7.1414 |
| 52 | 7.2111 |
| 53 | 7.2801 |
| 54 | 7.3485 |
| 55 | 7.4162 |
| 56 | 7.4833 |
| 57 | 7.5498 |
| 58 | 7.6158 |
| 59 | 7.6811 |
| 60 | 7.7460 |
| 61 | 7.8102 |
| 62 | 7.8740 |
| 63 | 7.9373 |
| 64 | 8.0000 |
| 65 | 8.0623 |
| 66 | 8.1240 |
| 67 | 8.1854 |
| 68 | 8.2462 |
| 69 | 8.3066 |
| 70 | 8.3666 |
| 71 | 8.4261 |
| 72 | 8.4853 |
| 73 | 8.5440 |
| 74 | 8.6023 |
| 75 | 8.6603 |
| 76 | 8.7178 |
| 77 | 8.7750 |
| 78 | 8.8318 |
| 79 | 8.8882 |
| 80 | 8.9443 |
| 81 | 9.0000 |
| 82 | 9.0554 |
| 83 | 9.1104 |
| 84 | 9.1652 |
| 85 | 9.2195 |
| 86 | 9.2736 |
| 87 | 9.3274 |
| 88 | 9.3808 |
| 89 | 9.4340 |
| 90 | 9.4868 |
| 91 | 9.5394 |
| 92 | 9.5917 |
| 93 | 9.6437 |
| 94 | 9.6954 |
| 95 | 9.7468 |
| 96 | 9.7980 |
| 97 | 9.8489 |
| 98 | 9.8995 |
| 99 | 9.9499 |
| 100 | 10.0000 |
📖 方向角・座標計算を会話で学ぶ →