π*(20根号3)^2*(2π*360°/40根号3π)/360°

问题描述:

π*(20根号3)^2*(2π*360°/40根号3π)/360°

π*(20根号3)^2*(2π*360°/40根号3π)/360°
=π*400*3*2π*/40根号3π
=20*3*π*/根号3
=20*π*根号3