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)