When 2 Sides Are Known

A triangle can be formed from 2 sides of any length.
The third side must be longer than the difference of the other 2 sides and
the third side must be less than the sum of the other 2 sides.

Example: If you have two lines of length 17 and 23 what would be the length of the third side to form a triangle?
Input 17 and 23 into ‘side 1’ and ‘side 2’ and then click on ‘2 sides’. The calculator then tells you that the third side must be greater than 6 and less than 40.

When 3 Sides Are Known

The longest side must be less than the sum of the other 2 sides.

Do you need to know if a triangle of sides two, nine and eight can be constructed?
Input 2, 9 and 8 into ‘side 1’, ‘side 2’ and ‘side 3’, then click on the ‘3 Sides’ button and you will see that a triangle of sides 2, 9 and 8 can be constructed.