Question

how do i solve this problem? medal will be given

http://media.education2020.com/evresources/2092536_4cafaa30-c3bc-46f9-b897-97c47941d943.png

Answer 1

What are you trying to solve?

Answer 2

oh sorry, i have to find the length of arc DGE

Answer 3

You have to find what portion of the circle you want so do 115/360=23/72

Answer 4

The circumference is 28pi and now you want 23/73 of that.

Answer 5

my answers are 161/18pi
343/36pi
343/18pi
343/9pi

Answer 6

so im not too sure how im supposed to get those

Answer 7

hmm....

Answer 8

i'll get you some help

Answer 9

@phi

Answer 10

can you bump your question so everyone can see it

Answer 11

in 7 minutes

Answer 12

ok

Answer 13

http://media.education2020.com/evresources/2092499_40a8915b-80e3-46dc-a149-5261526d5c6b.png could you help me with this one then?

Answer 14

sure

Answer 15

can you help us please @phi

Answer 16

***the length of arc DGE***

one way is to first figure out the length of the *whole circle*

can you do that ?

Answer 17

you use the famous formula C= 2 pi r

Answer 18

30?

Answer 19

30(pi)

Answer 20

r is 14

use 14 for r in the formula

C= 2 pi r

Answer 21

my bad i was looking at a different one. it would be 28(pi) then

Answer 22

Thankyou phi!

Answer 23

next, we need to find the fraction of the circle that is the arc DGE
(the "long" arc)

we know all the way around is 360º
but we don't go 360º. any idea how many degrees we do go ?

Answer 24

245? 115-360=245

Answer 25

yes. now we make the fraction
245/360

multiply 28 pi times 245/360

it does not look like a particularly nice number, so they may just want a decimal number for the answer ?

Answer 26

btw, I would do 360-115 = 245

Answer 27

my answers are 161/18pi
343/36pi
343/18pi
343/9pi

Answer 28

the answer is
\[ 28 \cdot \frac{245}{360} \pi\]
you have to simplify that

Answer 29

59.8647933434 i got this as my answer

Answer 30

you should not multiply by pi because all the answers are a number times pi

so you want a number 28*245/360 that multiplies pi

Answer 31

19.0555555556 then i get this

Answer 32

a calculator can change that to a fraction
or you can test the choices (change their fractions to a decimal)

Answer 33

or "manually" simplify the fraction by dividing top and bottom by the same factors
this will keep the answer as a fraction

Answer 34

so then it would be 343/18?

Answer 35

yes, (times pi)

Answer 36

okay thank you!
can i get your help on one more?

Answer 37

for the other question, uses

Answer 38

okay

Answer 39

so i get(32+x)x=(8+3x)3x

Answer 40

now solve for x.

Answer 41

so then after i distribute and do all that fun stuff i ended up with x=1, is that correct?

Answer 42

or you can plug 1 into the equation and see if it works

Answer 43

yea i got it, thanks again! you really helped me understand this better!