Is △pmr similar to △smn ? if so, which postulate or theorem proves these two triangles are similar? △pmr is similar to △smn by the ssa similarity theorem . △pmr is similar to △smn by the sas similarity theorem . △pmr is similar to△smn by the sss similarity theorem . △pmr is not similar to △smn . a triangle with vertices p m r. segment s n is inside the triangle. point s is on side p m. point n is on side m r. p s is equal to 8 feet. s m is equal to 14 feet. m n is equal to 21 feet. n r is equal to 12 feet.