Question

The quadrilateral ABCD is a parallelogram if pairs of consecutive angles are supplementary. Given the angles measures, prove that quadrilateral ABCD is a parallelogram by finding the value of x

Answer 1

REmember that

in a parallelogram, consecutive angles are supplementary

that means

.mmmm

therefore

substitute

120-2x+70+x=180

solve for x

2x-x=190-180

x=10

answer is option C