Length of arc ! Help please

Okay so i know the formula to length of an arc being 2 pie r (theta/360)

So could any 1 help me with this question and ill forever be grateful

If R is the Radius and Theta is the angles subtended by an arc find the length of the arc when

a. r = 2m and Theta = pie/6raD

b.r = 34m and Theta = 38 degrees 40'

Re: Length of arc ! Help please

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Re: Length of arc ! Help please

Re: Length of arc ! Help please

That is the picture of the question. Soroban i have never seen that method before, and firstly i would like to thank you for your input, however that formula is in a maths book, and the one that i have always used. your answer maybe correct but i am unsure of that method please could you elaborate.

please & thankyou

Re: Length of arc ! Help please

Quote:

Originally Posted by

**Eddie1994** Okay so i know the formula to length of an arc being 2 pie r (theta/360)

(Headbang)(Headbang)(Headbang) is spelled "pi" not "pie." (Headbang)(Headbang)

-Dan

Re: Length of arc ! Help please

Quote:

Originally Posted by

**Eddie1994** That is the picture of the question. Soroban i have never seen that method before, and firstly i would like to thank you for your input, however that formula is in a maths book, and the one that i have always used. your answer maybe correct but i am unsure of that method please could you elaborate.

please & thankyou

The circumference of a circle is . The arc length is a proportion of that, where the proportion is determined by the angle that is swept out. If the angle is in degrees, the proportion is , giving the arclength as . You should know that to convert angles in degrees to radians, you need to multiply by , so notice that , so that means , the much easier formula to work with.