Answer:
6. r = 21 cm
7. A = 155.5 m²
Step-by-step explanation:
7: Formula for arc length is;
S = (θ/360) × 2πr
We are given;
S = 51 cm
θ = 139°
Thus;
51 = (139/360) × 2π × r
Making r the subject;
r = (51 × 360)/(2π × 139)
r ≈ 21 cm
8) Area of sector is gotten from the formula;
A = (θ/360) × πr²
A = (220/360) × (π × 9²)
A = 155.5 m²