Three functions TRIangles, QUADangles and FIndAngles are given to find the angles of triangle and quadrilateral when vertices are known. TRIangles needs vertices in order 3X2 to calculate its three angles. QUADangles needs vertices in the order 4X2 to calculate its four angles. Vertices are input in anti-clock wise direction. The output is a row vector. When angles of many triangles and quadrilaterals are need to be evaluated, use FindAngles, it will take vertices and depending on the order of vertices gives angles.

The dot product between the vectors is used to calculate the angles.
theta = arc((a.b)/(|a|*|b|))

After finding the angles, make check of the angles using sum(angles). If vertices are of triangle sum will be 180, sum will be 360 for quadrilateral.

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