1.
設圈圈角為 a, tana = 2/3; tan2a = 2tana / 1-tana^2 = 4/3 / 5/9 = 12/5; 3*12/5 = 36/5.
2.
tan(∠PAR) = tan(∠PAM + ∠RAM) = (2/3 + 1/3) / 1-(2/3 * 1/3) = 1/ 7/9 = 9/7; ∠PAR ≒ 52
1.
設圈圈角為 a, tana = 2/3; tan2a = 2tana / 1-tana^2 = 4/3 / 5/9 = 12/5; 3*12/5 = 36/5.
2.
tan(∠PAR) = tan(∠PAM + ∠RAM) = (2/3 + 1/3) / 1-(2/3 * 1/3) = 1/ 7/9 = 9/7; ∠PAR ≒ 52
看了這個問題的人
也有瀏覽這些問題喔😉