A cone-shaped megaphone has a radius of 15 centimeters and a slant height of 20 centimeters. A megaphone has an open bottom. What is the lateral surface area of the megaphone, in square centimeters?

Question

Use 3.14 for pi. (1 point)
1,648.5 square centimeters
• 1,884 square centimeters
• 109.9 square centimeters
• 942 square centimeters

Answer 1

To find the lateral surface area of a cone-shaped megaphone, you can use the formula for the lateral surface area of a cone:

\[ \text{Lateral Surface Area} = \pi r l \]

where:

• \( r \) is the radius of the base,
• \( l \) is the slant height.

In this case:

• \( r = 15 \) centimeters,
• \( l = 20 \) centimeters,
• \( \pi \approx 3.14 \).

Now we can substitute the values into the formula:

\[ \text{Lateral Surface Area} = 3.14 \times 15 \times 20 \]

Calculating it step by step:

1. Calculate \( 15 \times 20 = 300 \).
2. Now, multiply \( 3.14 \times 300 = 942 \).

So, the lateral surface area of the megaphone is:

\[ \text{Lateral Surface Area} = 942 \text{ square centimeters} \]

The correct answer is 942 square centimeters.