A clock in the shape of a regular dodecagon has side measures of 5.5 inches. What is the clock’s area to the nearest tenth?

The clock's area is approximately
square inches.

1 answer

To find the area of a regular dodecagon (a 12-sided polygon), we can use the formula:

\[ \text{Area} = 3 \times (2 + \sqrt{3}) \times s^2 \]

where \( s \) is the length of a side.

Given that the side length \( s = 5.5 \) inches, we can substitute it into the formula:

\[ \text{Area} = 3 \times (2 + \sqrt{3}) \times (5.5)^2 \]

First, calculate \( (5.5)^2 \):

\[ (5.5)^2 = 30.25 \]

Next, calculate \( 2 + \sqrt{3} \). The value of \( \sqrt{3} \) is approximately 1.732, so:

\[ 2 + \sqrt{3} \approx 2 + 1.732 = 3.732 \]

Now, we substitute this value back into the area formula:

\[ \text{Area} \approx 3 \times 3.732 \times 30.25 \]

Calculating \( 3 \times 3.732 \):

\[ 3 \times 3.732 \approx 11.196 \]

Now multiply this by \( 30.25 \):

\[ \text{Area} \approx 11.196 \times 30.25 \approx 338.43 \]

Rounding to the nearest tenth, the area of the clock is approximately:

\[ \text{Area} \approx 338.4 \text{ square inches} \]

Thus, the clock's area is approximately 338.4 square inches.