Jika sudut AOB=30°,sudut COD=50°,CD=25 cm panjang Busur AB adalah

∠AOB/∠COD = Busur AB/Busur CD
30°/50° = Busur AB/25 cm
Busur AB 
= (30° × 25 cm)/50°
= (3 × 25 cm)/5
= 3 × 5 cm
= 15 cm