5)
c = sqrt(53)
CosA = 2/sqrt(53)
6)
tanA = 7/6
The right angle is always opposite the longest side (hypoteneuse).
So in this case, the hypoteneuse would be c, right angle would be C.
The other two angles A and B are oppsite sides a and b respectively. The positioning of these two sides is irrelevant because you're basically just flipping or turning the same triangle.