Question

What is cos P?  Right triangle PQR with a short leg measuring 5, a long leg measuring 12, and the hypotenuse as 13

Answer 1

It depends how you name the sides of triangle.
Look at picture at the result.

$cos\alpha=\frac{12}{13}\\ cos\beta=\frac{5}{13}$

PS. Sorry for my terrible drawing but I did it as fast as possible :)