Question

已知圆台的侧面积为S,上,下底面半径为R1,R2,求截得此圆台的圆锥的侧面积

Answer 1

该圆锥的侧面积与被截去的圆锥的侧面积之比为：R1^2:R2^2

设截得此圆台的圆锥的侧面积为X

则有(X-S):X=R1^2:R2^2

解得X=R2^2*S/(R2^2-R1^2)