BC = √3
旋转构成的几何体是底面半径 r = √3/2,高为3/2 的圆锥去掉一个高为1/2的圆锥.
体积 V= (π/3) r ^2 * (3/2-1/2) = π/4
表面积：大圆锥表面展成圆扇形的圆心角是 a = ( r / |BC| )* 2π = π
小圆锥表面展成圆扇形的圆心角是 b = ( r / |AB| )* 2π = √3 π
S = π * (√3)^2 /2 + (√3π）* 1^2 /2 = π (3/2 + √3/2)上来BC就求错了BC = √3没错吧？