Geometry

Arc Length

What is the Arc Length?

Length along a circular arc

This formula is widely used in geometry applications. Understanding when and how to apply it helps you interpret calculator results correctly and catch input errors before they propagate.

Formula

s = r * theta (radians)

Substitute known values into the formula above. Ensure all variables use consistent units before calculating.

Worked Example

r=5, theta=pi/2

Use the linked calculator below to try your own values and see step-by-step working.

When to Use This Formula

Apply the Arc Length when you need to length along a circular arc. It is a standard reference in geometry coursework, professional practice, and our linked calculators.

Tips & Common Mistakes

  • Draw and label diagrams before substituting values.
  • Ensure all lengths use the same unit.
  • Always verify critical results independently for engineering, medical, or legal applications.

Related Calculators

Further Reading

Browse the Formula Library for related formulas, or read educational articles on our Blog.