Question

Find circumferences and area of circle with a radius of 4.5cm ( use 3.14 for pi and round to tenth place and include proper units )

Answer 1

To find the circumference and area of a circle with a radius of 4.5 cm, we can use the following formulas:

1. **Circumference (C)** of a circle is given by the formula:
\[
C = 2 \pi r
\]
where \( r \) is the radius.

2. **Area (A)** of a circle is given by the formula:
\[
A = \pi r^2
\]

Using \( \pi \approx 3.14 \) and \( r = 4.5 \) cm:

### Circumference Calculation
\[
C = 2 \times 3.14 \times 4.5
\]
\[
C \approx 2 \times 3.14 \times 4.5 = 28.26 \text{ cm}
\]

Rounding to the nearest tenth:
\[
C \approx 28.3 \text{ cm}
\]

### Area Calculation
\[
A = 3.14 \times (4.5)^2
\]
Calculating \( (4.5)^2 \):
\[
(4.5)^2 = 20.25
\]
Now substituting back:
\[
A \approx 3.14 \times 20.25 = 63.57 \text{ cm}^2
\]

Rounding to the nearest tenth:
\[
A \approx 63.6 \text{ cm}^2
\]

### Final Answers
- Circumference: \( 28.3 \text{ cm} \)
- Area: \( 63.6 \text{ cm}^2 \)