A cone and cylinder same radius and same height.express ratio of their curved surface areas
cylinder: 2πr^2 + 2πrh = 2πr(r+h)
cone: πr^2 + πr√(r^2+h^2) = πr(r+s)
where s is the slant height
so, cone:cylinder
= πr(r+s) : 2πr(r+h)
= 1/2 (r+s)/(r+h)