侧面展开为扇形,圆心角为60度...,扇形半径R=圆锥母线长6扇形圆弧长L=2∏R(60度/360度)=2∏(6)(60度/360度)=2∏,圆锥底面圆周长=扇形圆弧长=2∏,圆锥底面圆半径r,2∏r=周长=扇形圆弧长=2∏,r=1,圆锥的表面积=侧面展开...