What’s the measure of arc AE

When turned about its axis of rotation, which shape could have created this three-dimensional object?

Gail is making costumes for a school play. each rabbit costume needs one and one half yards of white fur fabric, a yard of blue striped fabric, and a quarter of a yard of pink felt for the ears. g? ail needs to make eight rabbit man yards will she need, for the white fur fabric, blue striped fabric, and pink felt?

What is the missing step in this proof ?