Question

What is the measure of ∠ADC in quadrilateral ABCD?

Answer 1

we know that

The quadrilateral ABCD is a isosceles trapezoid. The properties of the isosceles trapezoid are as follows:

-The lower base angles are congruent.

So

m∠A=m∠D

m∠B=m∠C

m∠A+m∠B=$180$°

m∠D+m∠C=$180$°

therefore

m∠D=m∠A=$115$°

m∠B=$180$-m∠A

m∠B=$180$-$115$

m∠B=$65$°

m∠C=m∠B=$65$°

the answer is

The measure of angle ADC is $115$°

Answer 2

115 is the correct answer