They're congruent, so corresponding sides of corresponding congruent figures are congruent. A corresponds to P and C corresponds to R, so AC is congruent to PR
well for triangle DEF since E is on the top left, it should be on the bottom right. While F was on the bottom right, it would be on the top left where E originally was. The angles inside has the same situation with E and F, however D stills stays at the top because when reflected like a mirror, D stays at the top. Sorry it’s long and hope this helps!
