Answer:
∠FHG=120°
Step-by-step explanation:
first you calculate the angles of the triangle NGH
this is isoceles triangle, so there's 2 equal angles
and as shown, the 2 same angles are having 2 lines in each one, this 2 lines represents that the 2 angles are same
so both are 20°
any triangle has a sum of 180° of interior angles
so 180-(H+G)=the angle below N
180-(20+20)=140°
the angle below N is same as N because they're vertically opposite
140 is an exterior angle
and the exterior angle is equal to the 2 far angles
140=40+∠FHN
140-40=100°
so ∠FHN=100°
∠FHN+∠NHG=∠FHG
100+20=120°
so ∠FHG=120°
