Question

WILL FAN AND MEDAL!!!

Which circles have an area of 9pi m2?

Choose all answers that are correct.

A.
a circle with a radius of 3 m

B.
a circle with a diameter of 6 m

C.
a circle with a radius of 9 m

D.
a circle with a diameter of 9 m

Answer 1

The area of a circle is pi * r^2.

To help you get started checking options,

A) a circle with a radius of 3 m

Area = pi * 3^2 = 9 pi square meters.

Therefore, A is one of the correct answers.

Answer 2

@abelwell

Now, you check this one, okay?

B. a circle with a diameter of 6 m

Answer 3

i still dont get it. (i SUCK at math) could you explain it a bit more? @Directrix

Answer 4

On option B, the diameter is 6 so the radius is 3.

In the formula, replace r by 3 and see what you get for the area.

A = pi * r^2

Answer 5

9? (sorry if its wrong :/)

Answer 6

@Directrix

Answer 7

9 is correct if you add the pi, so 9 pi.
A = pi * r^2
------------
That means that Option B is correct.

Answer 8

On option C, the radius is 9 and when squared, it will be 81 along with the pi which is not correct.

Answer 9

On option D, the radius is 9/2 or 4.5 which when squared will not be 9.

Answer 10

@abelwell The two correct answers are what? Post what you think, okay?

Answer 11

A and B?

Answer 12

@Directrix

Answer 13

Correct.