Find the length of an arc of 40° in a circle with an 8 inch radius.

Question

hero · Answer

associated picture?

amistre64 · Answer

arc length is just a portion of circumference

anonymous · Answer

thnxx=) and no pic included

amistre64 · Answer

circumference = angle * r, any arc length is angle * r

amistre64 · Answer

turn the angle to rads tho

hero · Answer

Yeah, amistre has it. I was thinking about something else.

amistre64 · Answer

40 needs a pi, so 40*pi/180 = rads

amistre64 · Answer

and go ahead an multiply in the radius as well

hero · Answer

amistre, general formulas and approaches are always welcome

amistre64 · Answer

id have to think like a pigeon then; and i tend to think on the fly lol

anonymous · Answer

i dnt get it answer choices are 8/9  , 16/9 or 64/9

amistre64 · Answer

$$Arc_{length}=\frac{degree*pi*radius}{180}$$

amistre64 · Answer

I get 8/9 pi when I do it

anonymous · Answer

thnxx

amistre64 · Answer

40*8 = 320

320     32    16
--- =  -- = -- pi; i mighta inputed it wrong in me calculator; let me dbl chk
180     18     9

amistre64 · Answer

1 7/9 = 16/9  got it right that time lol

anonymous · Answer

lol ok

hero · Answer

In general, when finding the arc length of a circle when given the radius and degree, you may use the following formula: 

$$\frac{\theta}{360°} = \frac{x}{2 \pi r}$$ , x = arc length

anonymous · Answer

thnxx guys