(b) A diagram of Model 2, the hydraulic arm, is given in Figure 3 and shows a base AB of length 10cm and a vertical post BG. The angle ABG is a right angle. The vertical post is braced by a bar of length 17cm, represented by the line AC. A bar represented by the line FG can be raised or lowered by increasing or decreasing the length of a vertical hydraulic ram represented by the line ED. In its present position, ED is set at 20cm so that FG and AC are parallel. The Length of FE is 26 cm