The coordinates of a point P referred to axis meeting at an angle w are (h,k). Prove
that the length of the straight line joining the feet of the perpendiculars from P upon
the axes is
sinw√(h² + k² 2khcosw)
that the length of the straight line joining the feet of the perpendiculars from P upon
the axes is
sinw√(h² + k² 2khcosw)