For the first one, is it 10 or 5?
Cos T has the same value as Cos P = 10/15 = 2/3
So
Cos T = 2/3 = 6/x
Cross-multiply
2x = 3 * 6
2x = 18 divide both sides by 2
x = 9
Remember that sin (x) = cos (90 - x)
sin (23) = cos (90 - 23) = cos (67) ....so x = 67°
