# Sides of a Triangle: Open Middle Problem (V2)

- Author:
- Tim Brzezinski

- Topic:
- Geometry, Inequalities, Triangles

## Creation of this resource was inspired by this Open Middle problem from Christina Ploeckelman.

## Teachers and students: You can choose a different value for the fixed perimeter using the slider in the top left corner. Once you form a triangle from any three given segments, it will appear!

## How many triangles did you find? List all the sets of side lengths you found for the fixed perimeter you chose.

Is there a relationship among the 3 values that needs to be true in order for these 3 sides to form a triangle? If so, how would you describe it?

What causes 3 side lengths to *not* form a triangle? How would you describe it from what you've seen?