Question

When triangles ABC is reflected across line AB, the image is triangle ABD. Why is angle ACD congruent to angle ADB?

Answer 1

When we reflect the triangle ABC across AB, segments AD and AC are equal in length. Therefore, triangle ADC is an Isosceles triangle as it has two sides of the same measure.

Then, AC and AD are the legs of an Isosceles triangle; thus, angles The answer is An isosceles triangle has a pair of congruent angles.