X and Y are supplementary angles, both add to 180°.
The square angle is a right angle (90°) .
90 + 51 + z = 180°
Solve for z
z = 180 - 90 - 51
z = 39°
Also:
90 + 51 + x = 180
x = 180 -51 - 90
x = 39°
x and z are opposite angles ( opposite angles are equal)
Finally,
y + x = 180
y + 39 = 180
y= 180 - 39
Y= 141
Answers:
x = 39°
y= 141°
z= 39°
x and y are supplementary angles ( add up to 180°)