This is a PP=Problem Picture, i.e. a ggb file for a screenshot.
What is the shape? What is its perimeter?
The perimeter L is calculated in the algebra view.
The sliders are at increments 0.5. You can download this and change it.
I left rounding at 2 decimals so you can get close enough on DA for the age of the child. (I hit 4 "exactly" by accident.)
