Question

How do I solve this ?

Answer 1

For this, you just need to apply the cosine ratio, which states cos= adjacent side/hypotenuse.

Adjacent is the side right next to H (side GH)
and the hypotenuse is the longest side of the triangle (side FH)

So,
cos= 36/85
= 0.4235 (to 4 decimal places) !!