Question

An isosceles right triangle has two perpendicular legs of length 1 inch. It is rotated 360° about one of its legs in order to form a 3-dimensional figure. What is the best description of the 3-dimensional figure that is formed?

It is a triangle-based pyramid with four congruent faces
It is a cone with base radius of 1 inch and vertical height of 1 inch
It is a cone with base radius of 2 inches and vertical height of 1 inch
It is a cylinder with base radius of 1 inch and vertical height of 1 inch

Answer 1

It is a cone with base radius of 2 inches and vertical height of 1 inch

Answer 2

well if you rotate a triangle 360 degrees you're going to get a cone, which rules out A and D
you rotated around one of the one inch legs, which means the center is 1 inch, so the vertical height is 1 inch
the base radius is going to be the same as the leg, so 1 inch
your answer is B, it is a cone with base radius of 1 in and vertical height of 1 inch