Inscribe and Circumscribe Circles
in and around Triangles

pixelxy
Point 1
Point 2
Point 3


Or choose from any of these preset values:

Center of circle inside triangle
Center of circle outside triangle
Center of circle on triangle

To inscribe a circle within a triangle:

  1. Bisect all three angles
  2. Draw a circle with
    1. Center where all three angle bisectors intersect, and
    2. Radius equal to the closest distance from the center to all three sides.

To circumscribe a circle around a triangle:

  1. Draw the perpendicular bisectors of all three sides
  2. Draw a circle with
    1. Center where all three perpendicular bisectors intersect, and
    2. Radius equal to the furthest distance from the center to all three vertices.