Question

Circumference and Area of Circles Practice

Answer 1

1. Find the circumference of a circle with a radius of 4 cm.
Circumference = 2πr
Circumference = 2 x π x 4
Circumference ≈ 25.13 cm

2. Find the area of a circle with a diameter of 10 meters.
Radius = Diameter/2 = 10/2 = 5 meters
Area = πr^2
Area = π x 5^2
Area ≈ 78.54 square meters

3. Find the circumference of a circle with a diameter of 12 inches.
Radius = Diameter/2 = 12/2 = 6 inches
Circumference = 2πr
Circumference = 2 x π x 6
Circumference ≈ 37.70 inches

4. Find the area of a circle with a circumference of 30 cm.
Radius = Circumference / (2π) = 30 / (2 x π) ≈ 4.77 cm
Area = πr^2
Area = π x 4.77^2
Area ≈ 71.53 square cm

5. Find the circumference of a circle with an area of 50 square units.
Radius = √(Area/π) = √(50/π) ≈ 4.48 units
Circumference = 2πr
Circumference = 2 x π x 4.48
Circumference ≈ 28.12 units