5. The Triangle Inequality
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Use the Triangle Inequality Theorem to form three inequalities true for the triangle.
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We are given three expressions for measures of the sides of a triangle.
x, 4, 6
According to the Triangle Inequality Theorem, the sum of the lengths of any two sides of a triangle is always greater than the length of the third side. Using this theorem, we can write three true inequalities for this triangle.
| Inequality | Simplified | Solution Set |
|---|---|---|
| x+4 > 6 | x > 2 | x>2 |
| x+6 > 4 | x > -2 | x>-2 |
| 4+6 > x | 10 > x | x<10 |
Now we can graph the inequalities and find the set of common solutions.
As we can see, the lines overlap on the segment from 2 to 10. Therefore, the possible values of x are the following.
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