If you extend the perimeter by 3 feet in each direction, you will get a new rectangle 18 ft by 21 ft with a perimeter of 78 feet (18+21+18+21 = 78)
12ft
13.378 square meters.
213,000 gal / 7.48 gal /cubic foot =28,476cf /12ft(depth)=2373 sqft of surface area
144 inches
120
72
A square has 4 equal sides, so 4 x 12ft = 48ft
480 inches
56-ft
The area is 9 square feet.
12ft
2*(length + width) = 54 feet.
2(21+12) = 66 feet
Oh, dude, the perimeter of a rectangle is just adding up all the sides, so for a 12ft by 8ft rectangle, you just do 12 + 12 + 8 + 8, which equals 40 feet. It's like measuring the sides of a fence but with math instead of a tape measure.
Valerie is installing a 20ft by 12ft swimming pool surrounded by a 6ft deck. What is the total area of the deck?
864 ft
12 x pi (3.14) = 37.68ft2