First, when a diagonal line is drawn crossing two parallel ... known angles from the sum of a complete turn (360˚). Triangles have three interior angles. They are formed at the vertices (corners).

N.C. State and Duke earned regional No. 2 seeds, with UNC a No. 3. Here’s when the teams will play, and which teams they will host at their campus sites.

If a straight line has been split into three separate angles, it looks as if three corners of a triangle have been put together - just like in this video from BBC Bitesize: So if you had a missing ...