Question

The triangles in the diagram are congruent. If mF = 40°, mA = 80°, and mG = 60°, what is mB?

Answer 1

please post the diagram

Answer 2

since the triangles are congruent, they have the same corresponding angle measures

now, I will re-draw the two triangles in the same orientation so it's easier to match up corresponding angles

Answer 3

notice that, based on the positions of corresponding angles:

<A = <E
<C = <G
<B = <F

now, I will add in the angle measures we already know from the problem:



based on the given angle measures, as well as the angle congruencies we determined earlier, what is the measure of <B?