Question

Two adjacent angles of a parallelogram are congruent what is the measure of each?

Answer 1

let the angle are
x and other is y
then x+y=180
2x=180
=x=90. (x=y)

Answer 2

hi friend
here's your answer looking for

if two adjacent angle of a parallelogram are equal then

we can let the angles be x.

and the sum of that adjacent angle in the parallelogram will be 180 degree.

so,

$x + x = 180 \\ \\ 2x = 180 \\ \\ x = \frac{180}{2} \\ \\ x = 90$
so if in a parallelogram one angle is 90 degree then all angle will be 90 degree

so we can conclude that, the parallelogram is nothing but the rectangle.

so all the angle will be 90 degrees.

hope you are satisfied with my answer