Consider the reduction of the rectangle.

A larger rectangle has a length of 18 inches and width of 8 inches. A smaller rectangle has a length of x inches and width of 3 inches.

Write a proportion and then solve to find the missing measure of the reduced rectangle.

What two ratios can be used in the proportion?

What is the value of the missing measure?

1 answer

To set up the proportion for the reduction of the rectangle, we can compare the corresponding dimensions of the larger and smaller rectangles.

The larger rectangle has dimensions:

  • Length = 18 inches
  • Width = 8 inches

The smaller rectangle has dimensions:

  • Length = x inches
  • Width = 3 inches

The two ratios that can be used in the proportion can be written as:

\[ \frac{\text{Length of larger rectangle}}{\text{Length of smaller rectangle}} = \frac{\text{Width of larger rectangle}}{\text{Width of smaller rectangle}} \]

This gives us the proportion:

\[ \frac{18}{x} = \frac{8}{3} \]

Next, we can solve for \(x\) by cross-multiplying:

\[ 18 \cdot 3 = 8 \cdot x \]

Calculating \(18 \cdot 3\):

\[ 54 = 8x \]

Now, divide both sides by 8 to isolate \(x\):

\[ x = \frac{54}{8} = 6.75 \]

Therefore, the value of the missing measure (length of the smaller rectangle) is \(\boxed{6.75}\) inches.