Question

A circular lawn with a diameter of 20 square feet will be planted with grass seed. How many square feet are on the lawn?

31.4 ft squared
125.6 ft squared
314 ft squared
1,256 ft squared

Answer 1

314 ft squared

Explanation:

A = πr^2 = π · 102 ≈ 314.15927

Answer 2

314.159265359 ft squared or 314.16 ft squared rounded to the hundredths place. The closest result is option C.

Explanation:

The formula for finding the area of a circle is A=π×r^2.

Step 1: Find the radius which is half of the diameter. In this case, the radius is 10 feet.

Step 2: Square the radius that you found. In this case, the number will be 100ft or 10^2.

Step 3: Multiple this number by π, or 3.14 if your teacher allows it. So in this case, 100×π=314.159265359 or 314.16 rounded to the hundredths place. If you use 3.14... the answer is 314.

Step 4: You've got your answer. Hope this helps!