A cylinder has a surface area of 54 cm². If it were dilated using a scale factor of 1/2. what is the surface area of the new cylinder? (1 point) 2

1. 27 cm²

2. 6.75л ст²

3. 13.5 cm²

4. 108 cm²

1 answer

When a three-dimensional object is dilated using a scale factor \( k \), its surface area changes according to the square of the scale factor.

Given the original surface area \( A \) of the cylinder is 54 cm², and the scale factor \( k \) is \( \frac{1}{2} \), the surface area \( A' \) of the new cylinder can be calculated as follows:

\[ A' = A \cdot k^2 \]

Substituting the values:

\[ A' = 54 , \text{cm}^2 \cdot \left(\frac{1}{2}\right)^2 \] \[ A' = 54 , \text{cm}^2 \cdot \frac{1}{4} \] \[ A' = \frac{54}{4} , \text{cm}^2 = 13.5 , \text{cm}^2 \]

Therefore, the surface area of the new cylinder after dilation is 13.5 cm².

The correct answer is 3. 13.5 cm².