Let $P$ be a regular twelve-sided polygon. The number of right-angled triangles formed by the vertices of $P$ is (A) 60 (B) 120 (C) 160 (D) 220 .
Let $P$ be a regular twelve-sided polygon. The number of right-angled triangles formed by the vertices of $P$ is\\
(A) 60\\
(B) 120\\
(C) 160\\
(D) 220 .