一度等於 0.01745329252 弧度:
1° = π/180° = 0.005555556π = 0.01745329252 rad
因此,以弧度表示的角 α 等於以度數表示的角 α 乘以 pi 常數除以 180 度:
α(radians) = α(degrees) × π / 180°
或者
radians = degrees × π / 180°
將 25 度角轉換為弧度:
α(radians) = α(degrees) × π / 180° = 25° × 3.14159 / 180° = 0.436332313 rad
將 50 度角轉換為弧度:
α(radians) = α(degrees) × π / 180° = 50° × 3.14159 / 180° = 0.872664626 rad
將 90 度角轉換為弧度:
α(radians) = α(degrees) × π / 180° = 90° × 3.14159 / 180° = 1.5707963268 rad
所以以弧度為單位的角度 α 等於以度數為單位的角度 α 乘以 pi 常數除以 [180] 度。
α(radians) = (α(degrees) / 180°) × π
將 40 度角轉換為圓周率的弧度:
α(radians) = (α(degrees) / 180°) × π = (40° / 180°) × π
= (1/6) × π = π/6 rad = 0.22222222222π rad
將 90 度角轉換為圓周率的弧度:
α(radians) = (α(degrees) / 180°) × π = (90° / 180°) × π
= (1/6) × π = π/6 rad = 0.5π rad
將 120 度角轉換為圓周率的弧度:
α(radians) = (α(degrees) / 180°) × π = (120° / 180°) × π
= (1/6) × π = π/6 rad = 0.66666666667π rad