I think that each shelf will be 19 inches. Because 137 divided by 7 is 19 with the remainder of 4. Half of 4 is 2. Take 2 inches off of each end and that is the 4. So each shelf is 19 inches.
Answer:

Step-by-step explanation:
Check the picture
Answer:
d. 90°, 90°
Step-by-step explanation:
Both angles intercept 180° arc WZ. They are half the measure of the intercepted arc, hence both are 90°.
Answer:
3y^20/x^4
Step-by-step explanation: