G

#### Guest

##### Guest

I know how to solve it if it was four sides, but I'm not sure how to solve it if it's only for three sides.

G

I know how to solve it if it was four sides, but I'm not sure how to solve it if it's only for three sides.

We have

Code:

```
Brick wall
_______________
| |
Fence, length | | Fence, length x
x | |
|______________|
Fence,
length y
```

x+x+y= 500

2x + y = 500

You're confortable with rearranging this to get one variable the subject and plugging this into the equation for the area (A=xy), and differentiating and setting to zero?

With four sides you had 2y + 2x = 500. There isn't much difference, is there?

G

TchrWill, I'm not sure what you mean by derivitive, dA/dx or how you got 4x. But then again, I'm a bit slow in math.^^; I found the dimensions by:

2x + y = 500

A = x(500 - 2x)

-2x^2 + 500

x = -500/2(-2)

-500/-4 = 125

y = 500 - 2(125) = 250