How do I find the area of a regular octagon with perimeter of 48cm?

An octogon has 8 sides and each side is 48/8=6cm

The area of any regular polygon when the side length is known is:

A (n, s) = ns^2 / (4tan (180/n)) in this case

A (8,6) = 288 / (4tan22.5)

A=173.82cm^2 (to nearest hundredth of a cm^2)

A≈173.82cm² that's the answer.