R = 100, то R = a / (2 * sin120) sin120 = sin(180-60) = sin60
a = R * 2 * sin60 = 100√3, то
r = a / (2 * tg60) = 50
R = 100, то R = a / (2 * sin120) sin120 = sin(180-60) = sin60
a = R * 2 * sin60 = 100√3, то
r = a / (2 * tg60) = 50