三角星形线的两条互相垂直的法线的交点在哪里?Construct two mutually orthogonal tangents of the deltoid. Where do they meet?2三角星形线的两条互相垂直的切线的交点在哪里?Construct the part of the tangent of the deltoid intercepted by the curve....

“星形线”的英语可以翻译为：astroid，asteroid ...