Circumference = 2πr = 2π(3) = 6π cm.

Radius of the circle = side/2 = 8/2 = 4 cm. Area = πr² = π(4)² = 16π ≈ 50.24 cm².

Area of sector = (θ/360) * πr² = (60/360) * π(2)² = (1/6) * 4π ≈ 2.09 cm².

Area of sector = (θ/360) * πr² = (60/360) * π(5)² = (1/6) * 25π ≈ 13.09 cm².

Area = πr², so r = √(Area/π) = √(50.24/π) ≈ 4 cm.

Area = πr², so r² = Area/π = 113.04/π ≈ 36, thus r ≈ 6 cm, diameter = 12 cm.