Area of Circle Formula

Formula

In geometry, the area of a circle can be calculated using the following formula:

Area (A) = π x (r)^2

Where:

• A represents the area of the circle.
• π (pi) is a mathematical constant approximately equal to 3.14159.
• r is the radius of the circle, which is the distance from the center to the circumference.

Example Questions and Solutions:

If the radius of a circle is 5 cm, what is the area of the circle?

Solution 1:

        A = π x (5 cm)^2
        A = π x 25 cm^2
        Area ≈ 3.14159 x 25 cm^2 ≈ 78.54 cm^2
    

If the diameter of a circle is 12 m, what is the area of the circle?

Solution 2:

        Radius (r) = Diameter (d) / 2
        r = 12 m / 2 = 6 m
        A = π x (6 m)^2
        A = π x 36 m^2
        Area ≈ 3.14159 x 36 m^2 ≈ 113.10 m^2
    

If the area of a circle is 50 square inches, what is the radius?

Solution 3:

        r^2 = A / π
        r = √(A / π)
        r = √(50 square inches / 3.14159)
        r ≈ √(15.92) ≈ 3.99 inches
    

That's how you calculate the area of a circle using the formula, and here are solutions to three example questions. Remember, π is approximately 3.14159 for most calculations.