What is the measure of one interior angle of the decagon

In the figure below, segment ac is congruent to segment ab: triangle abc with a segment joining vertex a to point d on side bc. side ab is congruent to side ac which statement is used to prove that angle abd is congruent to angle acd? segment ad bisects angle cab. triangle acd is similar to triangle abd. segment ad is congruent to segment ac. angle cab is congruent to angle cba.

What is the length of the unknown leg in the right triangle ?

Brainlest answer can you find the area and circumference of a circle given the radius or diameter? if its yes or no explain why