The hypotenuse of a triangle is 3 inches longer than the longer leg. The shorter leg is 3 inches shorter than the longer leg. Find the lengths of the sides

1 answer

Let's denote the lengths of the sides of the triangle as follows:

  • Let \( x \) be the length of the longer leg.
  • Then, the hypotenuse can be expressed as \( x + 3 \) (3 inches longer than the longer leg).
  • The shorter leg can be expressed as \( x - 3 \) (3 inches shorter than the longer leg).

According to the Pythagorean theorem, we have:

\[ (\text{longer leg})^2 + (\text{shorter leg})^2 = (\text{hypotenuse})^2 \]

Substituting the expressions we have:

\[ x^2 + (x - 3)^2 = (x + 3)^2 \]

Now, let's expand and simplify the equation:

  1. Expand \( (x - 3)^2 \): \[ (x - 3)^2 = x^2 - 6x + 9 \]

  2. Expand \( (x + 3)^2 \): \[ (x + 3)^2 = x^2 + 6x + 9 \]

Now substitute these expansions back into the equation:

\[ x^2 + (x^2 - 6x + 9) = (x^2 + 6x + 9) \]

Combine like terms on the left side:

\[ 2x^2 - 6x + 9 = x^2 + 6x + 9 \]

Now, move all terms to one side:

\[ 2x^2 - 6x + 9 - x^2 - 6x - 9 = 0 \]

This simplifies to:

\[ x^2 - 12x = 0 \]

Factoring out \( x \):

\[ x(x - 12) = 0 \]

This gives us two solutions:

  1. \( x = 0 \) (not a valid side length)
  2. \( x = 12 \)

Now that we have \( x \), we can find the lengths of the sides:

  • Longer leg: \( x = 12 \) inches
  • Shorter leg: \( x - 3 = 12 - 3 = 9 \) inches
  • Hypotenuse: \( x + 3 = 12 + 3 = 15 \) inches

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

  • Longer leg: 12 inches
  • Shorter leg: 9 inches
  • Hypotenuse: 15 inches