Need this like right now please help me

Is δ pmr similar to δ smn ? if so, which postulate or theorem proves these two triangles are similar?

Which statement explains how you could use coordinate geometry to prove the opposite sides of a quadrilateral are congruent? a. use the slope formula to prove the slopes of the opposite sides are the same. b. use the slope formula to prove the slopes of the opposite sides are opposite reciprocals. c. use the distance formula to prove the lengths of the opposite sides are the same. d. use the distance formula to prove the midpoints of the opposite sides are the same.

How are algebraic expressions evaluated using substitution?