Question

PPPLLLEEEAAASSSEEE, help me! What is the arc length of arc CD in the circle below?

Answer 1

The picture given for the question.

Answer 2

@ganeshie8 @azolotor @BangkokGarrett .... Do any of you know how to do this? i know it has something to do with a formula i have, but every time I have dine that formula it's wrong.

Answer 3

The length of a circular arc is given by:\[L=\frac{\alpha \pi}{180} r\] or \[L=\frac{\alpha}{360} C\]You can find the arc length by substituting in known values.

Answer 4

In this case the first one will be easier since you are already given the radius.

Answer 5

So would it look like this:
L=15*45*3.14 / 360?

Answer 6

It would be \[\frac{45\deg\times \pi}{180} \times15ft\]

Answer 7

So the answer would be 11.75?

Answer 8

Yes.

Answer 9

okay cool, thanks! :)

Answer 10

Can you help me with something else? @twvogels

Answer 11

Yes, go ahead.

Answer 12

The circle shown below has AB and BC as its tangents.
If the measure of arc AC is 140°, what is the measure of angle ABC?
My options are:
60°
40°
70°
50°

Answer 13

The only thing that makes since is that it is 140, but thats not an option

Answer 14

Is AC the arc length or the length across?

Answer 15

Um... arc length i think

Answer 16

Ah...I get it now. Its the angle between them. This is just a double angle problem. I was making it harder than it has to be. ABC is just \[\frac{1}{2}(220-140)=40\]

Answer 17

Where did u get 220 from?

Answer 18

360-140=220

If its 140deg from A to C the short way, then its 220deg the long way.

Answer 19

Ok? I'm sorry. I am confused why would you need to know that there is 220 degrees everywhere else but where the triangle is covering.

Answer 20

That's just the way the formula works.

Answer 21

So you subtract 360 from the given degree than subtract that from the given degree again and multiply that by .5 and it will give you your answer?

Answer 22

Yes, the formula is: \[m=\frac{1}{2}(major-minor)\]