Circular Sector Area Calculator

Circular Sector Diagram
r: 0 units θ: 0° Area = 0 Area = (θ/360°) × π × r²

About Circular Sector Area Calculation

What is a Circular Sector?

A circular sector is a portion of a circle enclosed by two radii and an arc. It resembles a "pie slice" and is defined by its radius and the central angle it subtends.

Formula for Circular Sector Area

The formula to calculate the area of a circular sector is:

\[A = \frac{\theta}{360°} \pi r^2\]

Where:

  • \(A\) is the area of the circular sector
  • \(\theta\) (theta) is the central angle in degrees
  • \(\pi\) (pi) is approximately 3.14159
  • \(r\) is the radius of the circle

Calculation Steps

  1. Identify the radius (r) of the circle.
  2. Determine the central angle (θ) in degrees.
  3. Divide the central angle by 360°.
  4. Multiply the result by π (pi).
  5. Multiply by the square of the radius.
  6. The final result is the area of the circular sector in square units.

Example

Let's calculate the area of a circular sector with a radius of 5 units and a central angle of 60°:

  1. Given:
    • Radius (r) = 5 units
    • Central Angle (θ) = 60°
  2. Apply the formula: \(A = \frac{\theta}{360°} \pi r^2\)
  3. Substitute the values: \(A = \frac{60°}{360°} \pi (5)^2\)
  4. Calculate:
    \(A = \frac{1}{6} \pi (25)\)
    \(A = \frac{25\pi}{6}\)
    \(A \approx 13.09\) square units (rounded to 2 decimal places)

Visual representation:

Radius (r) = 5 units θ = 60° Calculation Steps: Area = (θ/360°) × π × r² Area = (60°/360°) × π × 5² Area = 13.09 square units Area = 13.09 sq units

Therefore, the area of the circular sector is approximately 13.09 square units.