altitude高
                        depth深度
                        side边长
                        circumference,perimeter周长
                        radian弧度
                        surface area 表面积
                        volume体积
                        arm直角三角形的股
                        cros ssection横截面
                        center of acircle圆心
                        chord弦
                        radius半径
                        angle bisector角平分线
                        diagonal对角线
                        diameter直径
                        edge棱