Question

A dartboard has a diameter of 18 inches. What is its radius and circumference (C)?

Select all that apply.

Select 2 correct answer(s)
Question 6 options:

radius = 26 inches


C = 9π
square inches


radius = 9 inches


radius = 3 inches


C = 18π
square inches


C =26π
square inches

Answer 1

To find the radius and circumference of a dartboard with a diameter of 18 inches, we can use the following formulas:

1. **Radius (r)**: The radius is half of the diameter.
\[
r = \frac{\text{diameter}}{2} = \frac{18 \text{ inches}}{2} = 9 \text{ inches}
\]

2. **Circumference (C)**: The circumference of a circle is given by the formula:
\[
C = \pi \times \text{diameter} = \pi \times 18 \text{ inches} = 18\pi \text{ inches}
\]

Now, let's check the options given:

- **Radius = 26 inches** (Incorrect; the radius is 9 inches)
- **C = 9π square inches** (Incorrect; the circumference is 18π inches)
- **Radius = 9 inches** (Correct)
- **Radius = 3 inches** (Incorrect; the radius is 9 inches)
- **C = 18π square inches** (Correct)
- **C = 26π square inches** (Incorrect; the circumference is 18π inches)

The two correct answers are:

1. Radius = 9 inches
2. C = 18π square inches