Question

What is the perimeter of the basement floor ? and What is the area of the basement floor, please help :)

Answer 1

To get the perimeter, add up all the side lengths.
(The unknown side lengths are both 13 ft because 22-9 and 31-18)
31 + 22 + 18 + 13 + 13 + 9 = 106 ft
The perimeter is 106 ft.

For area, what I would do is find the entire rectangle (without the empty space) then find the area of empty space and subtract it out.
Area of entire rectangle: 31 · 22 = 682 ft²
Area of empty space: 18 · 13 = 234 ft²
Area of basement floor: 682 - 234 = 448 ft²
The area of the basement floor is 448 ft².