Hey! Can someone help me?

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.

Nine more than four times a number is the same as one less than twice the number. find the number?

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*