CIRCLES-1

Find radius if the length of an arc of the circle is ^∏/₁₅ cm.

Solution

L= ^∏/₅  , r = ?

L = ∏r

      180

^∏/5  = ∏r

         180

180  x ^∏/5  = ∏r  x   180   

                    180

180∏  = ∏r 

     5      

                    

180 ∏  = ∏r 

    15∏  ∏

180   =  r 

    15      

r = 36cm

Hence radius is 36 cm

TRY THIS………………..

Find radius if the length of an arc of the circle is ^∏/₂₀ cm.