Answer:
Well we need to see the axis of rotation there must be a picture or something to depend on since you provided very few information or whatsoever.
If your picture of information has the cone cut from the middle then it's a circle and if it's from top to bottom it's an isosceles triangles.
Here's a picture I found on the internet to help you understand it better ^-^
Sorry if I didn't help but Good luck!
