Let L, M, N be the feet of the perpendiculars drawn from a point P(7, 9, 4) on the x, y and z-axes respectively. The coordinates ofL, M and N respectively are 

Since L is the foot of perpendicular from P on the x-axis, its y and z-coordinates are zero. So, the coordinates of L is (7, 0, 0). Similarly, the coordinates of M and N are (0, 9, 0) and (0, 0, 4), respectively.