Transcript text: Given: The coordinates of triangle $P Q R$ are $P(0,0), Q(2 a, 0)$, and $R(2 b, 2 c)$.
Prove: The line containing the midpoints of two sides of a triangle is parallel to the third side.
As part of the proof, find the midpoint of $\overline{\mathrm{PR}}$.
(b, c)
$(a-b, c)$