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Whats the linear measure of an arc whose central angle is 80* on a circle having a radius of 18 meters?

Rose98  Jul 12, 2014

Best Answer 

 #7
avatar+92751 
+8

I really liked this question Rose.

I'd do it CPhill's way.

the whole circumference it 2pi*r

But you only have 80degrees out of a total of 360 degrees in the whole cirlce.

so the answer must be given by

$$arc\;length= \frac{80}{360}\times 2\pi r => \frac{80}{360}\times 2\pi\times 18$$    etc

Melody  Jul 12, 2014
 #1
avatar+8258 
0

Good question. Do you know about the formula? Or may you give a hint?

  

DragonSlayer554  Jul 12, 2014
 #2
avatar+841 
+3

arc length/circumference=degree measure/360*

Rose98  Jul 12, 2014
 #3
avatar+8258 
0

Okay. I'll try.

  

DragonSlayer554  Jul 12, 2014
 #4
avatar+8258 
0

First, what is circumference, and what is arc length?

  

DragonSlayer554  Jul 12, 2014
 #5
avatar+841 
+3

2r(pi)   r=radius

Rose98  Jul 12, 2014
 #6
avatar+87293 
+8

The total circumference is 2*pi*18  = 36pi

Note that we only want (80/360)ths = (2/9)ths of this.

So, (80/360)*36pi  = (2/9)*36pi = 8pi

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The above is a "corrected" answer!!...Mainly because I forgot what I was doing!!!

 

CPhill  Jul 12, 2014
 #7
avatar+92751 
+8
Best Answer

I really liked this question Rose.

I'd do it CPhill's way.

the whole circumference it 2pi*r

But you only have 80degrees out of a total of 360 degrees in the whole cirlce.

so the answer must be given by

$$arc\;length= \frac{80}{360}\times 2\pi r => \frac{80}{360}\times 2\pi\times 18$$    etc

Melody  Jul 12, 2014
 #8
avatar+841 
0

Thank you guys:) I am really getting this whole Geometry thing now! :D

Rose98  Jul 12, 2014
 #9
avatar+92751 
+5

Geometry is fun when you get the hang of it!  

Melody  Jul 12, 2014
 #10
avatar+841 
0

Never thought it would be, but now I am seeing the fun part :)

Rose98  Jul 12, 2014
 #11
avatar+11847 
0

I wish i too could see the fun part of Geometry like u Rose!

But im happy u saw it!lol!

rosala  Jul 13, 2014

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