Triangle Inequality

What is the possible length of the third side of a triangle?

Enter in the two given sides of a triangle. Then move point B around (or animate it using the button) to see the endpoint of the third side traced along the x-axis.

Is a triangle possible with the given sides?

See if you can create a triangle with the given sides. Change the side lengths in the app below and move the blue points to see if you can create a triangle. To see if a triangle can be formed, click the button "Show answer"

Triangle Inequality Practice

Determine whether a triangle can be formed with the given side lengths. Determine the range of the third side of a triangle given the lengths of the two other sides.