3分之2π的圆心角所对弧长是2πCM求半径

问题描述:

3分之2π的圆心角所对弧长是2πCM求半径

3分之2π的圆心角= 2/3 *180° = 120°
2 π R * 120 /360 = 2π
R = 3 CM