Circumference = 2πr, so r = Circumference / (2π) = 62.8 / (2π) ≈ 10 cm.

Area = πr², so r = √(Area/π) = √(78.5/π) ≈ 5 cm.

Circumference = πd = π(10) ≈ 31.4 m.

Area of sector = (θ/360) * πr² = (90/360) * π(4)² = (1/4) * 16π = 4π ≈ 12.56 cm².

Distance = √[(x2 - x1)² + (y2 - y1)²] = √[(7 - 3)² + (1 - 4)²] = √[16 + 9] = √25 = 5 units.

Arc length = (θ/360) * 2πr = (60/360) * 2π(3) = (1/6) * 6π = π ≈ 3.14 m.