Question

(05.02) Find the measure of angle x in the figure below:
55
45
80
55
100

Answer 1

To find x, first find y.

In a triangle, all the angles add up to 180. So we can create the equation:

45+55+y=180
100+y=180
y=80

Since x and y are vertical angles, that mean they are equal so that means angle x is also 80.