Let $A, B, C$ be the feet of the perpendiculars from a point $P$ on the $xy, yz,$ and $zx$-planes respectively. Find the coordinates of $A, B, C$ for the following points $P$:
$(3, 4, 5), (-5, 3, 7), (4, -3, -5)$

(N/A) We know that on the $xy$-plane,$z=0$; on the $yz$-plane,$x=0$; and on the $zx$-plane,$y=0$.
Thus,the coordinates of the feet of the perpendiculars from point $P(x, y, z)$ are $A(x, y, 0)$ on the $xy$-plane,$B(0, y, z)$ on the $yz$-plane,and $C(x, 0, z)$ on the $zx$-plane.
$(i)$ For $P(3, 4, 5)$:
$A(3, 4, 0), B(0, 4, 5), C(3, 0, 5)$
(ii) For $P(-5, 3, 7)$:
$A(-5, 3, 0), B(0, 3, 7), C(-5, 0, 7)$
(iii) For $P(4, -3, -5)$:
$A(4, -3, 0), B(0, -3, -5), C(4, 0, -5)$