Given:

__
AB

__
DE

m∠BAE=70°, AD=AE.
Find: m∠DAE.
Sorry if format is terrifiying or broken.

1 answer

angles BAE and DEA are alternate interior angles, so m∠DEA=70°.

AD=AE, so ∆DAE is isosceles. That means m∠ADE=70°.

m∠DAE is thus 180-70-70 = 40°