Two sides of a triangle measure 3.7 and 8.2. Apply the Triangle Inequality Theorem to find a possible measure of the third side.(1 point)

Responses

4.5
4.5

4.2
4.2

3.5
3.5

5.5

:)

2 answers

To apply the Triangle Inequality Theorem, we need to remember that for any triangle with sides of lengths \(a\), \(b\), and \(c\), the following inequalities must hold:

  1. \(a + b > c\)
  2. \(a + c > b\)
  3. \(b + c > a\)

Let the two sides of the triangle be \(a = 3.7\) and \(b = 8.2\), and the third side be \(c\).

Now we will apply the Triangle Inequality Theorem:

  1. For \(a + b > c\): \[ 3.7 + 8.2 > c \implies 11.9 > c \implies c < 11.9 \]

  2. For \(a + c > b\): \[ 3.7 + c > 8.2 \implies c > 8.2 - 3.7 \implies c > 4.5 \]

  3. For \(b + c > a\): \[ 8.2 + c > 3.7 \implies c > 3.7 - 8.2 \implies c > -4.5 \] (This inequality is trivial since \(c\) must be positive.)

Now, combining the results, we have: \[ 4.5 < c < 11.9 \]

From the provided options, \(4.5\) is not a valid measure (since it cannot be equal). Therefore, the possible measures for \(c\) are any value greater than \(4.5\) but less than \(11.9\).

The following options are given:

  • 4.5
  • 4.2
  • 3.5
  • 5.5

Only \(5.5\) satisfies \(c > 4.5\).

So, the possible measure of the third side is 5.5.

Good job