The figure shows triangle pqr and line segment ab, which is parallel to qr:
triangle pqr has a point a on side pq and point b on side pr. the line ab is parallel to the line qr.

part a: is triangle pqr similar to triangle pab? explain using what you know about triangle similarity. (5 points)

part b: which line segment on triangle pab corresponds to line segment qr? explain your answer. (3 points)

part c: which angle on triangle pab corresponds to angle q? explain your answer. (2 points)

(i need on b. i already know a and c)