Answer:
h = 55
Explanation:
the sum of the 3 angles in a triangle = 180°
the 2 unknown interior angles = 180 - 2h ( straight angle ), hence
the sum of the 3 angles
180- 2h + 180 - 2h + 40 = 180
400 - 4h = 180 ( subtract 400 from both sides )
- 4h = - 220 ( divide both sides by - 4 )
h = 55