I need help guys plsss

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

this is false ^.^ lol

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!