Question

NOTE: Angles not necessarily drawn to scale.

Answer 1

The answer is 13!! :)

Answer 2

The entire plane is 360°
Each side (top & bottom) is 180°
Each 1/4 section is 90°
With the information given that the angle opposite to x is 77°
And the total angle of that quadrant is 90°
By using the laws of angles.

Then you can calculate 90°-77°=x
So x=13°