Apply the Triangle Inequality Theorem and determine which option could be the third side of a triangle if the first two sides measure 4 and 6.(1 point)

Responses

11
11

9
9

1
1

2

1 answer

To determine the possible lengths of the third side of a triangle when the first two sides measure 4 and 6, you can use the Triangle Inequality Theorem. According to this theorem, the sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Let's denote the lengths of the two sides as \( a = 4 \) and \( b = 6 \), and the length of the third side as \( c \). The Triangle Inequality Theorem gives us the following inequalities:

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

Substituting the values we have:

  1. \( 4 + 6 > c \) → \( 10 > c \) → \( c < 10 \)
  2. \( 4 + c > 6 \) → \( c > 2 \)
  3. \( 6 + c > 4 \) → \( c > -2 \) (This inequality is always true for positive \( c \))

Combining the inequalities from the first two conditions, we find:

\[ 2 < c < 10 \]

Now, let's evaluate each of the given options:

  • 11: Not valid (greater than 10)
  • 9: Valid (between 2 and 10)
  • 1: Not valid (less than 2)
  • 2: Not valid (equal to 2, must be greater than 2)

The only option that could be the length of the third side is 9.