jari jari 100cm π= 3,14 panjang busur 31,4cm berapakah sudut pusat lingkaran?

panjang busur = a/360° × 2 × π × r
3,14 cm = a/360° × 2 × 3,14 × 100 cm
3,14 cm = a/360° × 628 cm
a/360° = 3,14 cm / 628 cm
a/360° = 1/20
a = 1/20 × 360° = 18°