Math Is Fun Forum

MoyMarian

Member

Registered: 2009-01-10

Posts: 29

Solid Mensuration XIII

A right circular cylinder is inscribed in a right circular cone of altitude a and base b. Find the radius of the cylinder if its lateral area is equal to the lateral area of the cone which surmounts the cylinder.

Muggleton

Member

Registered: 2009-01-15

Posts: 65

Re: Solid Mensuration XIII

Let the radius of the cylinder be r. Then its height is a(b−r)/b (by similar triangles). So

Last edited by Muggleton (2009-01-16 15:07:58)