[问答题]
The area, A , of a
8o e(p5n4r npg ihzw ai)q9a60given square can be represented by the function
$A(P)=\frac{P^{2}}{16}$, $\quad P \geq 0$,
where P is the perimeter of the square.
The graph of the function A , for $0 \leq P \leq 20$ , is shown below.
1. Find the value of A(20) .
2. On the grid above, draw the graph of the inverse function, $A^{-1}$ .
3. In the context of the question, explain the meaning of $A^{-1}(4)=8$ .