Find the angle of parallelogram ABCD if angle A = 2 angle.

A parallelogram is a quadrilateral in which opposite sides are pairwise parallel and equal.

The opposite angles of the parallelogram are also equal to each other:

∠А = ∠С;

∠В = ∠Д.

Since the sum of the degree measures of the angles adjacent to one side of the parallelogram is 180º, and the value of the angle ∠A is equal to the value of two angles ∠B, we will express it as follows:

x is the degree measure of the angle ∠В;

2x – degree measure of angle ∠A;

x + 2x = 180;

3x = 180;

x = 180/3 = 60;

∠В = 60º;

∠А = 60º · 2 = 120º.

Answer: the angle a ∠A is equal to 120º, ∠B is equal to 60º.