Two sides of a triangle have the same length. The third side measures 6 m less than twice that length. The perimeter of the triangle is 14 m. Find the lengths of the three sides.

1 answer

Let the length of each of the two equal sides be \( x \). According to the problem, the third side measures \( 2x - 6 \).

The perimeter of the triangle is given by the sum of the three sides, which is:

\[ x + x + (2x - 6) = 14 \]

Simplifying this expression, we get:

\[ 2x + 2x - 6 = 14 \]

Combining like terms leads to:

\[ 4x - 6 = 14 \]

Next, we isolate \( 4x \) by adding 6 to both sides:

\[ 4x = 20 \]

Now, dividing by 4 gives us:

\[ x = 5 \]

Now that we have the length of the two equal sides, we can find the length of the third side:

\[ \text{Third side} = 2x - 6 = 2(5) - 6 = 10 - 6 = 4 \]

Thus, the lengths of the three sides of the triangle are:

  • Two equal sides: \( 5 \) m each
  • Third side: \( 4 \) m

To summarize, the lengths of the sides are:

  • \( 5 \) m
  • \( 5 \) m
  • \( 4 \) m

We can double-check that the perimeter is correct:

\[ 5 + 5 + 4 = 14 \text{ m} \]

Therefore, the solution is confirmed: the lengths of the three sides are \( 5 \) m, \( 5 \) m, and \( 4 \) m.