Unproctored Placement Assessment

Question 22

Find the area and the circumference of a circle with a radius of 9 ft. Use the value 3.14 for [tex]\pi[/tex], and do not round your answers. Be sure to include the correct units.

Area:

Circumference:



Answer :

To determine the area and circumference of a circle with a radius of 9 feet, you can follow these steps:

1. Identify the values given in the problem:
- Radius ([tex]\( r \)[/tex]) of the circle is 9 feet.
- Use the value of π ([tex]\( \pi \)[/tex]) as 3.14.

2. Calculate the area of the circle:
- The formula for the area [tex]\( A \)[/tex] of a circle is:
[tex]\[ A = \pi r^2 \][/tex]
- Substitute [tex]\( r = 9 \)[/tex] feet and [tex]\( \pi = 3.14 \)[/tex] into the formula:
[tex]\[ A = 3.14 \times 9^2 \][/tex]
- Compute [tex]\( 9^2 \)[/tex]:
[tex]\[ 9^2 = 81 \][/tex]
- Multiply by π:
[tex]\[ A = 3.14 \times 81 = 254.34 \text{ square feet} \][/tex]

3. Calculate the circumference of the circle:
- The formula for the circumference [tex]\( C \)[/tex] of a circle is:
[tex]\[ C = 2 \pi r \][/tex]
- Substitute [tex]\( r = 9 \)[/tex] feet and [tex]\( \pi = 3.14 \)[/tex] into the formula:
[tex]\[ C = 2 \times 3.14 \times 9 \][/tex]
- Perform the multiplication:
[tex]\[ C = 6.28 \times 9 = 56.52 \text{ feet} \][/tex]

Thus, the area of the circle is [tex]\( 254.34 \text{ square feet} \)[/tex] and the circumference is [tex]\( 56.52 \text{ feet} \)[/tex].

- Area: [tex]\( 254.34 \text{ square feet} \)[/tex]
- Circumference: [tex]\( 56.52 \text{ feet} \)[/tex]