Answer:
z = 20°
Explanation:
You want the measure of inscribed angle z that intercepts an arc of 40°.
Inscribed angle
The measure of an inscribed angle is half the measure of the arc it intercepts:
z = 40°/2
z = 20°
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Additional comment
Inscribed angles that intercept the same arc have the same measure:
x = z = 20°
The other angles in the figure are ...
w = y = 108°/2 = 54°
This means the two triangles are similar, and the measure of their third interior angle is 180° -20° -54° = 106°.
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