Area = Length x width
So 20x15=300
Area=300ft
Perimeter= adding the sides so 20ft +20ft +15ft +15ft=30 -if it was a rectangle if it wasn’t then just add up all the sides don’t forget to add the 2 (squared)
Perimeter=30ft
Volume= length x width x height(deep)
So It’d be 20x15x6=18,000
Volume=18,000 ft