m<y + m<z + m<w + m<x = 360

The sum of the interior angles of a quadrilateral is 360 degrees.

Subtraction property the equality

A quadrilateral with opposite angles congruent is parallelogram.

Simplify (Combine like terms)

choose the correct answer and explain why

m<y + m<z = 180

Explanation: Since the sum of the interior angles of a quadrilateral is 360 degrees, and the opposite angles of a parallelogram are congruent, then m<y + m<z must equal 180 degrees.