Apothem

Written by Jerry Ratzlaff on . Posted in Geometry

  • apothemApothem is the length of a line perpendicular from the center to the midpoint of the side of a regular polygon.
  • A irregular polygon has no center so there can be no apothem.

Given Radius formula

\(A= r cos {\left( \frac {180} {n} \right)} \)

Where:

\(A\) = apothem

\(r\) = radius

\(cos\) = cosine in degrees

\(n\) = number of sides

Given Edge formula

\(A=\frac {s} {2 tan \left( \frac {180} {n} \right) } \)

Where:

\(A\) = apothem

\(s\) = edge (side length)

\(tan\) = tangent in degrees

\(n\) = number of sides