A region in the plane which gives the same volume whether

Question

Question: 1. The arc length of the curve y = x⁵ between x = 0 and x = 2 is less than 32.

2. A region in the plane which gives the same volume whether rotated about the x-axis or the y-axis.

3. Two different curves from (0, 0) to (10, 0) that have the same arc length.