prhatikan gambar .. besar aob =120° dan aoc=100° dan pnjng busur ac=60 cm hitunglh pnjang busur bc

bc
= 360° - 220°
= 140°

100° = 60 cm
10° = 6 cm

140° = 6 cm x 14 = 84 cm

< boc = 360 - 120 -100
= 140°

rumus perbandingan
bc/ <boc = ac / < aoc
bc/ 140 = 60/100
bc = 60/100 . 140
bc= 84 cm

semoga mmbantu