Question

The diameter of the larger circle is 20.4 cm.
The diameter of the smaller circle is 10.8 cm.

What is the approximate area of the shaded region?



A.
326.7 cm²

B.
289.4 cm²

C.
235.1 cm²

D.
72.3 cm²
http://static.k12.com/calms_media/media/1419000_1419500/1419371/1/c4e26a94203d8ae90d1065d72cde797bf3ba1a4c/MS_PA_130922_171142.jpg

Answer 1

@iGreen

Answer 2

Subtract the diameters.

20.4 - 10.8 = ?

Answer 3

Then divide by 2 to find the radius..

Answer 4

First we need to calculate the area of the larger circle, and then the area of the smaller circle. And then if we subtract them, we can find the area of the shaded area.

Answer 5

9.6

Answer 6

Yes, now divide by 2.

Answer 7

@TheSmartOne That's the harder way :P

Answer 8

4.8

Answer 9

Yes, now plug it into:

\(A = \pi r^2\)

Answer 10

72.3456

Answer 11

My bad..lol.

Answer 12

@TheSmartOne is correct.

Answer 13

:P xDD

Answer 14

It's not a circle..so it doesn't have a radius xD

Answer 15

oops

Answer 16

\(A = \pi r^2\)

20.4 / 2 = 10.2

Plug it in for the radius

Answer 17

First find the radius of the 2 circles

The diameter of the larger circle is 20.4 cm.
The diameter of the smaller circle is 10.8 cm.

Divide those two values by 2 first.

Answer 18

\((3.14)(10.2^2) - (3.14)(5.4^2)\)

Answer 19

10.8=326.6859
20.4=91.5624

Answer 20

Correct.

Answer 21

Now subtract them.

Answer 22

And basically your answer will be

\(\sf\Large \pi (\frac{20.4}{2})^2- \pi(\frac{10.8}{2})^2\)

Answer 23

326.6859 - 91.5624 = ?

Answer 24

235.1235

Answer 25

Correct

Answer 26

Correct :) Now just round it :)

Answer 27

C!

Answer 28

Correct :)

Answer 29

Thanks guys!

Answer 30

Any time :)

Answer 31

No problem, Happy to Help \(\Huge\ddot\smile\)

Answer 32

Pshhh, I knew that....

Answer 33

Lol