Find all the angles of the parallelogram if one angle is 20 degrees greater than the other.

1. Let’s denote the degree measure of the smaller angle of the parallelogram through x.

2. Define the degree measure of the greater angle of the parallelogram:

(x + 20˚).

3. Using the property of the angles of the parallelogram, compose and solve the equation:

(x + 20˚) + x = 180˚;

x + 20˚ + x = 180˚;

2x + 20˚ = 180˚;

2x = 180˚ – 20˚;

2x = 160˚;

x = 160˚: 2;

x = 80˚.

4. The degree measure of the smaller angle of the parallelogram is x = 80˚.

5. What is the degree measure of the greater angle of the parallelogram?

x + 20˚ = 80˚ + 20˚ = 100˚.

Answer: The angles of the parallelogram ABCD are 80˚, 100˚, 80˚, 100˚.