Answer:
21 square yards
Step-by-step explanation:
Let's remember that the formula of the area of a rectangle is A = L*W, where L is the length and W the width.
In this case, L = 21 feet and W = 9 feet.
Therefore, A = 21 feet * 9 feet = 189 square feet
We need the answer in square yards. We know that 1 feet equals 1/3 yard (1 feet = 1/3 yard)
As we need square yards, we just square the equation above.
1^2 square feet = (1/3) ^2 square yards
1 square feet = 1/9 square yards
The area is 189 square feet, so we just multiply by 189 on both sides to do the conversion to square yards.
189 square feet = 189*1/9 square yards
189 square feet = 21 square yards
The area of the flower bed is 21 square yards