The point D is on the intersection of lines CC
and AA
. Therefore, we
begin by placing a mass of 1 at C. Then, for line BC to balance at A
a mass
of 3 must be placed at B. Similarly, for line AB to balance at C
a mass of 9
must be placed at A. This configuration is shown in Figure 11.22.
The total mass is 13 (1 + 3 + 9), therefore