Calculate missing angles in triangles, quadrilaterals, polygons and circles involving perpendicular bisectors and tangents as part of National 5.

Learn about and revise the different angle properties of circles described by different circle theorems with GCSE Bitesize AQA Maths.

Ivo G. Rosenberg, Frank Stenger, A Lower Bound on the Angles of Triangles Constructed by Bisecting the Longest Side, Mathematics of Computation, Vol. 29, No. 130 (Apr., 1975), pp. 390-395 ...