Question

I don’t understand this can you give a quick simple explanation

Answer 1

Given the question in the image, the following are the solution steps to answer the question.

STEP 1: Explain the procedure

Given that a two dimensional shape can be rotated about the y-axis to create a cylinder which has a smaller diameter than height. Whenever a vertical line with equation x=a is rotated about y axis from y =b to y=c we get a right circular cylinder. The cylinder would have radius as a and height as c-b.Whenever we want the diameter to be less than height we must select a,b,c such that

Hence, the answer is "Rectangle"