tolong jawab no 123 pake caranya dong please butuh banget

1. 60/360 × 2× 3,14× r = 10
1/6 × 6,28 × r = 10
6,28 × r/6 = 10
r = 6 × 10 / 6,28 = 9,5
panjang busur BC = 150/360 × 2 × 3,14 × 9,5 = 24,85 cm