Perimeter and area

For a rectangle with fixed perimeter $20$ which has the largest area?

Let $w$ and $h$ describe the rectangle. The perimeter satisfies the constraint $2w + 2h = 20$. The value of $w$ can be adjusted:

$w =$1.0

Perimeter and area

For a rectangle with fixed area $25$ which has the smallest perimeter?

Let $w$ and $h$ describe the rectangle. The area satsfies the constraint $w \cdot h = 25$. The value of $w$ can be adjusted:

$w =$3.0