Answer:
30degrees
Step-by-step explanation:
Using the theorem;
The angle at the vertex is half the difference of the angles at its intercepted arc. Mathematically,
<3 = 1/2(arc XY - arc WZ)
Given
arc XY = 85degrees
arc WZ = 25 degrees
Substitute the given values into the formula;
<3 = 1/2 (85-25)
<3 = 1/2(60)
<3 = 60/2
<3 = 30degrees
Hence the measure of <3 is 30degrees