There is a river of lava. Laurel A crazy person wants to build a wall to enclose a rectangular zone that borders the river of lava. She has 80 feet of material to build this wall, but obviously cannot build a wall on the lava side (because that would be dangerous). What is the largest area that can be enclosed

The largest area that can be enclosed is 400.

Step-by-step explanation:

We know that Laurel A crazy person has 80 feet of material to build this wall. Since it wants to limit the rectangular zone, let the lengths of the rectangles be x and y. So we have:

We conclude that the largest surface is obtained when x = 20 and y = 20.

Then we get the square shape, but we know that the square is the special shape of the rectangle.

We calculate:

The largest area that can be enclosed is 400.