CirArrow: Circular Arrow Tool

Use this tool to calculate shape end-points when modeling circular arrows using CAD software. The output of this tool is a simple set of points which define the requested parametrized circular arrows. Therefore, this tool should be useful for nearly every CAD program that supports elementary objects and shapes, such as lines and polygons.

I thank my friend and roommate Sabrina Kabakov for her help in determining the mathematics behind this tool.

Arrow Parameters

The following completely parametrize a circular arrow about some center point:

  • Center point — (h, k)
  • Radius — r
  • Start angle — θ
  • Tail sweep angle — Ψt
  • Head length — d
  • Head width — w
Diagram of parameters relating to circular arrow

Parameter Input

Use the form below to input parameters for a single arrow: