Triangle Inequality Theorem
10th Grade · Math · 45 min
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Learning Objective
I can determine if three side lengths form a triangle using the triangle inequality theorem.
- 1
The triangle inequality theorem states that the sum of the two smaller sides of a triangle must be greater than the longest side.
- 2
To find the possible range for the third side of a triangle, you must subtract the two given sides to find the lower bound and add them to find the upper bound.
- 3
If given two sides of a triangle of lengths 7 and 5, the third side (x) must fall in the range 2 < x < 12.
