Answer:
Explanation:
1. 56 + 81 = 137
2. The exterior angle theorem means that the 2 angles within a triangle that is on the opposite side of the angle outside the triangle could be added to find the angle that is outside of the triangle.
3. 56 and 81 are on the opposite side of the "x" outside the triangle which means that they could be added together which equals 137 degrees.
Hope this helps!