Calculate the bisector

Online calculator for calculating the bisector (median) of triangles

Calculate the length of the bisectors


The median or bisector of a triangle is a line segment, that connects a corner point with the center point of its opposite side. This function calculates the length of the bisector.

More information about bisecting lines can be found at the bottom of this page.


Length of the bisector

 Input
Side a
Side b
Side c
Decimal places
 Results
Bisector A
Bisector B
Bisector C

Formulas for calculating the bisecting line


The median or bisector of a triangle is a line segment that connects a corner point with the midpoint of its opposite side

Since the median of a triangle can be drawn from any corner point, each triangle has three medians

Unlike heights, medians do not form a right angle with the side they intersect

A bisector cuts the triangle into two smaller triangles of equal area and height

An angle bisector of a triangle is a straight line through a vertex which cuts the corresponding angle in half. The three angle bisectors intersect in a single point, the incenter, usually denoted by I, the center of the triangle's incircle. The incircle is the circle which lies inside the triangle and touches all three sides. Its radius is called the inradius.

The centroid cuts every median in the ratio 2:1, i.e. the distance between a vertex and the centroid is twice the distance between the centroid and the midpoint of the opposite side.


P is the centroid cuts the medians in a ratio of 2:1

The lengths of bisectors of triangles \(a \), \(b \) and \(c \) are calculated using the following formulas

\(\displaystyle Pa=\frac{\sqrt{2(b^2+c^2)-a^2}}{2}\)
\(\displaystyle Pb=\frac{\sqrt{2(c^2+a^2)-b^2}}{2}\)
\(\displaystyle Pc=\frac{\sqrt{2(a^2+b^2)-c^2}}{2}\)
Is this page helpful?            
Thank you for your feedback!

Sorry about that

How can we improve it?