i need help asap, please give the correct answer

Answer:
w = 6
Step-by-step explanation:
Midsegment theorem states that "a segment connecting midpoints of the two sides of a triangle is parallel and half in measure of the third side."
By this theorem,
ST = 2(PR)
w + 6 = 2w
(w + 6) - w = 2w - w
w = 6