31. In a convex pentagon , all sides are equal, and the angle is half the angle . Find the angle .
Problem 321
Official solution
76.31. Answer. . Hint. Apply to the given pentagon a triangle , equal to triangle .
31. In a convex pentagon , all sides are equal, and the angle is half the angle . Find the angle .
76.31. Answer. . Hint. Apply to the given pentagon a triangle , equal to triangle .