Question

MEDAL FOR BEST ANSWER
The circumference of a circle is 30 pi cm. Find the diameter, the radius, and the length of an arc of 170 degrees

Answer 1

Please help :(

Answer 2

RULE #1: What is the formula for the circumference of a circle?

Answer 3

umm not sure :( @Tajar

Answer 4

3.14 times radius?

Answer 5

C= 2πr

Answer 6

They give us C

Answer 7

okay so the equation would be 30pi =2pi times r? divide the pi's to get the radius?

Answer 8

yes!

Answer 9

good job!

Answer 10

Then you get 2r=30

Answer 11

so the radius is 15?

Answer 12

yes!

Answer 13

and then you know the diameter, right?

Answer 14

wouldnt it be 30?

Answer 15

d=2r

Answer 16

so yes

Answer 17

yes

Answer 18

Now....do you know the RULE to find the length of an arc?

Answer 19

add them together?

Answer 20

Here is the RULE:

Answer 21

The length of arc n degrees = n degrees/360 degrees (2pi x r)

Answer 22

sorrrry something just bit me

Answer 23

So basically an arc is just a percentage of the entire 360 degree circumference of a circle

Answer 24

so 170/360 x 2pi (15)?

Answer 25

OH NO!

Answer 26

ARE YOU OK?

Answer 27

Yeah, I am.

Answer 28

yes

Answer 29

Great Job!!

Answer 30

i got 85 pi over 6..

Answer 31

So (170/360) = .47

Answer 32

Then .47 (30pi)
=14.1pi

Answer 33

you got the correct answer...just finish divding 85/6

Answer 34

how did you get 30 pi?

Answer 35

2pi x r = 2 x pi x 15 = 30 pi

Answer 36

oh ok
thanks!

Answer 37

yw :)

Answer 38

I might call you back for more help! I suck at this :(

Answer 39

Did you solve the arc length yet?

Answer 40

yes I did

Answer 41

Okay - I joined this discussion so late I thought I skipped over it.