answer:
the triangle shown in question 5 is congruent. also known as SSS (side,side,side). the reason why its SSS is because if you look at the triangle, you see 3 different lines on the outside. one has only one line, one has 2 lines, and one has 3 lines. this is an indication that the triangle is congruent. you could not say AAA (angle,angle,angle) because that does not mean the triangles are considered congruent.
hopefully this helped :)