Enter the lengths of Side1 and Side2 into the calculator to determine the midsegment of the triangle.

Midsegment Formula

The following formula is used to calculate the midsegment of a triangle:

Midsegment = (Side1 + Side2) / 2 


  • Midsegment is the length of the midsegment of the triangle
  • Side1 is the length of one side of the triangle
  • Side2 is the length of another side of the triangle

To calculate the midsegment of a triangle, add the lengths of two sides of the triangle and divide the sum by 2.

What is a Midsegment?

A midsegment in geometry refers to a line segment that connects the midpoints of two sides of a triangle, forming a smaller, similar triangle within the original. This line segment is parallel to the third side of the triangle and is half the length of that side. The midsegment theorem, a fundamental concept in geometry, states this relationship. The theorem is used to solve various geometrical problems and proofs. It’s important to note that every triangle has three possible midsegments, each corresponding to a different pair of sides.

How to Calculate Midsegment?

The following steps outline how to calculate the Midsegment of a triangle.

  1. First, determine the lengths of two sides of the triangle.
  2. Next, add the lengths of the two sides together.
  3. Then, divide the sum by 2 to find the midsegment length.
  4. Finally, calculate the midsegment of the triangle.
  5. After inserting the lengths and calculating the result, check your answer with the given example problem.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Side 1 length = 8

Side 2 length = 12