McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
5. The Triangle Inequality
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Exercise 13 Page 449

6 m

Practice makes perfect
We have been given the following side lengths. 5 m and 11 m We can find the range of possible lengths for the third side of the triangle, x m, using the Triangle Inequality Theorem. This theorem tells us that the sum of the lengths of any two sides of a triangle is greater than the length of the third side.

XY+YZ>XZ YZ+XZ>XY XZ+XY>YZ Applying this theorem to the given side lengths, we have three inequalities. I:&5+11>x ⇒ 16 > x II:&11+x>5 ⇒ x > -6 III:&x+5>11 ⇒ x > 6 The range for the possible lengths of the third side can be found by looking at the overlapping regions for these inequalities.

In interval notation, this can be written as the following compound inequality. 6 m< x< 16 m