nathallya30 17/03/2018 R^2 = 12^2 + 20^2 + 2×12×20×cos.60R^2 = 144 + 400 + 480×1/2R^2 = 144 + 400 + 240R = R = 28
nathallya30
R^2 = 12^2 + 20^2 + 2×12×20×cos.60
R^2 = 144 + 400 + 480×1/2
R^2 = 144 + 400 + 240
R =
R = 28