Find circumference 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, you can use the following formulas:

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

2. Area \( A \) of a circle:
   \[ A = \pi r^2 \]

Given that the radius \( r \) is \( 4.5 \) cm and using \( \pi \approx 3.14 \):

Calculation of Circumference:

\[ C = 2 \cdot 3.14 \cdot 4.5 \] \[ C = 6.28 \cdot 4.5 \] \[ C = 28.26 \text{ cm} \]

When rounded to the tenth place, the circumference is: \[ C \approx 28.3 \text{ cm} \]

Calculation of Area:

\[ A = 3.14 \cdot (4.5)^2 \] \[ A = 3.14 \cdot 20.25 \] \[ A = 63.585 \text{ cm}^2 \]

When rounded to the tenth place, the area is: \[ A \approx 63.6 \text{ cm}^2 \]

Summary:

• Circumference: \( \approx 28.3 \text{ cm} \)
• Area: \( \approx 63.6 \text{ cm}^2 \)