In the figure shown, ABCD is a square and CDE is equilateral. What is the degree measure of CBE?
Note that DC = CE
And DC = BC
So BC = CE
Angle BCE = angle BCD - angle ECD = 90 - 60 = 30°
And triangle CEB is isoceles with BC = CE
So angle CBE = [180 - 30] / 2 = 150/2 = 75°
