**Interactive Slope of a line. Click and drag points to see formula in action


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    Home
    Algebra
    Math Games
  • Decimals in Space
  • Fraction Balls
  • Integers in Space
  • Math Man
  • Number Balls
  • Geometry
    Interactive
    Trigonometry
    Jobs
  • Tutoring jobs
  • New York Tutoring Jobs
  • White Plains, NY
  • Westchester County, NY
  • Chicago Math Jobs
  • Philadelphia
  • Teacher Resources
    On FaceBook!

    S = rθ Formula and Equation

    Radian Measure and Arc of a Circle

    There is a formula that relates the arc length of a circle of radius, r, to the central angle ,θ in radians.

    Formula for S =rθ

    The picture below illustrates the relationship between the radius, and the central angle in radians. The formula is
    s = rθ where s represents the arc length, θ represents the central angle in radians and r is the length of the radius.
    Picture of s = rTheta in a circle
    Demonstration of the Formual s=rθ
    The interative demonstration below illustrates the relationship between the central angle of a circle, measured in radians, and the length of the intercepted arc. Just click and drag the points.

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    What is the value of the arc length s in the circle pictured below?

    Answer

    What is the value of the arc length s in the circle pictured below?
    Answer
    Calculate the measure of the arc length s in the circle pictured below?
    Answer
    Calculate the measure of the arc length s in the circle pictured below?
    Answer

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