A trapezoid with an area of [tex]$36 \, \text{in}^2$[/tex] is dilated with a scale factor of [tex]$k=0.8$[/tex]. What is the area of the new trapezoid?

A. [tex]45 \, \text{in}^2[/tex]
B. [tex]28.8 \, \text{in}^2[/tex]
C. [tex]23.04 \, \text{in}^2[/tex]
D. [tex]56.25 \, \text{in}^2[/tex]



Answer :

Sure, let's work through this problem step-by-step.

1. Understand the dilation concept: Dilation changes the size of a shape but preserves the proportion of its sides. When a shape is dilated with a scale factor [tex]\( k \)[/tex], the area of the dilated shape scales by [tex]\( k^2 \)[/tex].

2. Identify the given data:
- Original area of the trapezoid, [tex]\( A_{\text{original}} = 36 \, \text{in}^2 \)[/tex]
- Scale factor, [tex]\( k = 0.8 \)[/tex]

3. Apply the area scaling factor: When a shape is scaled by a factor [tex]\( k \)[/tex], the new area [tex]\( A_{\text{new}} \)[/tex] can be calculated using the formula:
[tex]\[ A_{\text{new}} = A_{\text{original}} \times k^2 \][/tex]

4. Calculate the new area:
[tex]\[ A_{\text{new}} = 36 \, \text{in}^2 \times (0.8)^2 \][/tex]

5. Calculate [tex]\( (0.8)^2 \)[/tex]:
[tex]\[ (0.8)^2 = 0.64 \][/tex]

6. Multiply the original area by 0.64:
[tex]\[ A_{\text{new}} = 36 \, \text{in}^2 \times 0.64 = 23.04 \, \text{in}^2 \][/tex]

Therefore, the area of the new trapezoid after dilation is [tex]\( 23.04 \, \text{in}^2 \)[/tex].

Of the given options, the correct answer is:
[tex]\( 23.04 \, \text{in}^2 \)[/tex].