Answer:
90°
Explanation:
In the picture, if you make a shape of the angles (including x°, y°, and the undefined angle), it is a circle, therefore it is 360° because a circle is 360°.
First, you add 50° + 40°, which gives you 90°. The undefined angle, which is 50° + 40° vertical angle is also 90° Therefore x° and y° must equal 90°.