besar sudut AOB = 40° dan besar sudut AOC = 60°. jika panjang busur AB = 9 cm, maka panjang busur AC adalah?

Dik : AB = 9
AC = ......
AOB = 40 derajat
AOC 60 derajat
Dit : panjang ac........?
penyelesaian
rumus : =AB/AC = AOB/AOC
= 9/AC = 40/60
= 9/AC = 2/3
= 2 AC = 3×9
= 2 AC = 27
= AC = 27/2
= AC = 13,5 cm.