AO and OC are both radii of the circle. Length AO = Length OC Draw the line OB. It creates two triangles OCB and OAB. These share the length OB.

Any point P with coordinates (\(x,~y\)) on the circumference of a circle can be joined to the centre (0, 0) by a straight line that forms the hypotenuse of a right-angle triangle with sides of length ...