[tex]hyx^{2} =bx^{2} +hx^{2}[/tex]First you get the length PX
secondly you use the sine rule a\sin A= b\sin B=c\sin C
hence hy = 30
you take 30\sin 90=18\X
cross multiply
sin 90 × 18 = 30×X
sin 90 = 1
1×18=30X
18\30=30X\30
0.6=X
then sin~1 0.6
answer 36.8699 as angle p
then get cos 36.8699
