Answer:
Step-by-step explanation:
We know that the length is four times the width, so:
We also know the area, which is 324 m². The formula for area:
Insert the known values:
Solve for w. Simplify by removing parentheses:
Divide 4 from both sides to isolate the variable:
Find the square root of both sides:
The width is 9 m.
We know the width. Now find the length by using the area formula and inserting known values:
Solve for l. Divide both sides by 9:
The length of the rectangle is 36. (You can check: 4 times 9 is 36)
Now find the perimeter:
Insert values:
The perimeter is 90 m.