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-2, 10, 12
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-2+10 > 12 | x > 4 | x>4 |
| x-2+12 > 10 | x > 0 | x>0 |
| 10+12 > x-2 | 24 > x | x<24 |
Now we can graph the inequalities and find the set of common solutions.
As we can see, the lines overlap on the segment from 4 to 24. Therefore, the possible values of x are the following.
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