$$\begin{aligned} & \text { Area }=\int_1^{25} 4 \sqrt{x} d x-\frac{1}{2} \times(5-1) \cdot 4-\frac{1}{2} \times(25-5) \times 20 \\ & =4\left[\frac{2}{3} x^{\frac{3}{2}}\right]_1^{25}-8-200=\frac{368}{3} \\ & \Rightarrow 3 A=368 \end{aligned}$$