Question

What is the area of this circle? (Express your answer using π.)

Circle with 10 ft diameter - assessment graphic

A.
A = 100π ft2

B.
A = 5π ft2

C.
A = 10π ft2

D.
A = 25π ft2

Answer 1

1 easier way: Use the area of a circle formula which is π⋅r^2, since it gives us a diameter of 10ft we need a radius which we divided 10 in half by 2 to get a radius of 5. And we plug it in π⋅(5)^2 which gives an answer of 25π ft2.

2nd way: Formula is now 1/4π⋅d^2, where the above one ↑ has r^2 we are using is the same way but different. So we know the diameter is 10 → 1/4π⋅(10)^2 which also gives us an answer of 25π.

So the answer to your question is D. 25π ft^2

hope it helps. ^^