Question

If the base is k+7 and the perimeter is 4k+20, what's the height and area of the rectangle?

Answer 1

Have a look:

Explanation:

Considering your rectangle:

We see that:
`2x+2k+14=4k+20`
`2x=2k+6`
So:
`x=k+3`

Area will be:
`A=basexxheight=(k+7)(k+3)=k^2+3k+7k+21=k^2+10k+21`