The Triangle Inequality Theorem states that for any triangle with sides of lengths \(a\), \(b\), and \(c\), the following inequalities must hold:
- \(a + b > c\)
- \(a + c > b\)
- \(b + c > a\)
Given two sides of the triangle, 3.7 and 8.2, let's denote them as \(a = 3.7\) and \(b = 8.2\). We can find a range of possible values for the third side \(c\) using the triangle inequality:
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From \(a + b > c\): \[ 3.7 + 8.2 > c \implies 11.9 > c \implies c < 11.9 \]
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From \(a + c > b\): \[ 3.7 + c > 8.2 \implies c > 8.2 - 3.7 \implies c > 4.5 \]
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From \(b + c > a\): \[ 8.2 + c > 3.7 \implies c > 3.7 - 8.2 \implies c > -4.5 \quad \text{(this inequality does not constrain \(c\))} \]
Combining the relevant inequalities, we find that: \[ 4.5 < c < 11.9 \]
Now, let's examine the provided options for possible measures of the third side:
- 3.5: does not satisfy \(c > 4.5\).
- 4.5: does not satisfy \(c > 4.5\) (it is equal, not greater).
- 4.2: does not satisfy \(c > 4.5\).
- 5.5: satisfies \(4.5 < c < 11.9\).
Therefore, the only valid possible measure of the third side is 5.5.