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

Answer 1

https://www.dropbox.com/s/nu37d4qt54hihf3/Screenshot%202015-06-09%2014.32.43.png?dl=0

Answer 2

\[Area~of~larger~circle-Area~of~smaller~circle\]

Answer 3

find the area of both circles, then subtract the small circle form the big one

Answer 4

oh i kinda maybe sorta get this 1 so
20.4 x 3.14
10.8 x 3.14 then u sutract the 2

Answer 5

Do you remember the area of a circle formula? We've gone over it twice now

Answer 6

64.056 - 33.912
and yes A= π x r ^2

Answer 7

And you know that \[\Large Radius=\large \frac{1}{2}Diameter\] right?

Answer 8

√

Answer 9

\[\sqrt{?}\]

Answer 10

right!

Answer 11

√ = radius= 1/2 diameter

Answer 12

\[\sqrt{}=\color{aqua}r\color{red}a\color{blue}d\color{green}i\color{yellow}u\color{brown}s?\]

Answer 13

long story short i was saying right but witch a check mark ^u^

Answer 14

Oh. I was wondering what sqrt's had to do with it.

Answer 15

sorry, for the confusion

Answer 16

Anyways, the questions give us the diameters. We have to halve those to get the radius so that we can plug into the area of a circle equation.

Answer 17

\[(\pi*\frac{20.4}{2}^{2})-(\pi*\frac{10.8}{2}^{2})\] is our overall equation for this problem.

Answer 18

Divide before squaring though

Answer 19

653.3712 - 183.1248 = 470.2469

Answer 20

?

Answer 21

Divide BEFORE squaring. 20.4/2 = 10.2. 10.2^2=?

Answer 22

aww man

Answer 23

104.04

Answer 24

104.04*pi=?

Answer 25

326.6856

Answer 26

Now repeat the process for 10.8

Answer 27

366.2496

Answer 28

10.8/2=?

Answer 29

oh 5.4

Answer 30

5.4^2=?

Answer 31

29.16

Answer 32

29.16*pi=?

Answer 33

91.5624

Answer 34

now subtract

Answer 35

so 91.5624 - 29.16 = 62.4024

Answer 36

waot no!!!

Answer 37

Come on man. Look at my very first reply in the thread

Answer 38

I was wrong sorry

Answer 39

91.5624 -366.2496

Answer 40

326-91 bruh

Answer 41

oh :/ sorry. 235 C

Answer 42

yeah that'd be it

Answer 43

Thank you!

Answer 44

No problem :)