In the figure below, angle y and angle x form vertical angles. Angle x forms a straight line with the 50° angle and the 40° angle. Write and solve an equation to determine the measure of angle y.

Answer 1

Since vertical angles are congruent, we have:

y = x

Since angle x forms a straight line with the 50° angle and the 40° angle, the sum of the angles is 180°. Therefore:

x + 50 + 40 = 180

x + 90 = 180
x = 90°

Therefore, the measure of angle y is:

y = x
y = 90°