A trapezoid has a base of 10 inches, sides of 8 inches, and a top length of 4 inches. Suppose the trapezoid dilated using a scale factor of 1/2. What is the perimeter of the dilated trapezoid?

15
11
60
30

1 answer

To find the perimeter of the dilated trapezoid, we first need to find the perimeter of the original trapezoid before dilation.

The sides of the trapezoid are as follows:

  • Base 1: 10 inches
  • Base 2 (top): 4 inches
  • Side 1: 8 inches
  • Side 2: 8 inches

Now we calculate the perimeter of the original trapezoid:

\[ \text{Perimeter} = \text{Base 1} + \text{Base 2} + \text{Side 1} + \text{Side 2} \]

Substituting in the values:

\[ \text{Perimeter} = 10 + 4 + 8 + 8 = 30 \text{ inches} \]

Next, we apply the dilation using a scale factor of \( \frac{1}{2} \). Dilation affects all linear dimensions, including lengths. Thus, the new lengths after dilation will be:

  • New Base 1 = \( 10 \times \frac{1}{2} = 5 \) inches
  • New Base 2 = \( 4 \times \frac{1}{2} = 2 \) inches
  • New Side 1 = \( 8 \times \frac{1}{2} = 4 \) inches
  • New Side 2 = \( 8 \times \frac{1}{2} = 4 \) inches

Now, we calculate the perimeter of the dilated trapezoid:

\[ \text{New Perimeter} = \text{New Base 1} + \text{New Base 2} + \text{New Side 1} + \text{New Side 2} \]

Substituting in the new lengths:

\[ \text{New Perimeter} = 5 + 2 + 4 + 4 = 15 \text{ inches} \]

Thus, the perimeter of the dilated trapezoid is \( \boxed{15} \) inches.