Answer:
x = 78
Step-by-step explanation:
Look at Triangle DBH. Two of its angles are known. Let y = <DHB
47 + 31 + y = 180 All triangles have 180 degrees. Combine the left.
78 + y = 180 Subtract 78 from both sides.
78-78+y = 180-78 Combine
y = 102
Notice that y + x = 180 They form a straight line.
102 + x = 180 Subtract 102 from both sides.
x = 78
You should notice that x is an exterior angle. (I didn't at first).
Exterior angles are the sum of the two remote interior angles which in this case, are 31 + 47 = 78
Much shorter and much easier.
