Question

If quadrilateral ABCD is an isosceles trapezoid, then which of the following statements must be true?

Answer 1

D) < B + <D = 180

Explanation:

isosceles trapezoid

<A = <D

<B = <C

so <A + <C = 180

or < B + <D = 180

Answer 2

B+D = 180

Explanation:

An isosceles trapezoid mean the base angles are equal. That means angles A and D are equal. Then angles C and B are equal. Therefore opposite angles are supplementary

A+C = 180

B+D = 180

But since A and D are equal

D+C = 180

B+ A = 180