The equal sign with a tilde signifies that line segment FG and segment HF are congruent. If two sides of a triangle are congruent, then the triangle is an isosceles triangle. It then provides the top angle at F where the two congruent sides meet, which is 140 degrees. In an isosceles triangle, the angles between one congruent side and a non-congruent side are equivalent angle measures, meaning that to find the measure of angle H, you simply have to subtract 140 from 180 then divide that quantity by 2 for the measure of one of the two congruent angles, in this case equaling 20 degrees.
First, draw the triangle and label the sides and angles. (See the picture attached)
The red lines on sides FG and HF indicate that the sides are congruent since this is an isosceles triangle. Isosceles triangles have two congruent sides and angles.
All angles add up to 180 degrees. You were already given 140 for angle F. So, use to find angle h, subtract 140 from 180 and divide by 2.
