Question

What is the approximate circumference of a circle that has a radius of 63? Use 3.14 for π
and express your answer to the hundredths place.(1 point)


What is the approximate circumference of a circle that has a diameter of 20? Use 3.14 for π
and express your answer to the tenths place.(1 point)


A circle has an approximate circumference of 574 meters
. What is the circle’s diameter, rounded to the nearest tenth? Use 3.14
for π
. (1 point)
meters

If a circle has a radius of 38 inches
, what is its approximate circumference to the nearest hundredths? Use 3.14
for π
.(1 point)
inches


The radius of a circle is 75 mm. What is the approximate area of the circle? Write your answer to the tenths place. Use 3.14 for π
.(1 point)
mm2

Answer 1

uhm 3 and 5 are wrong

Answer 2

Let's solve each part of your question one at a time.

1. **Circumference of a circle with radius 63:**

The formula for circumference \(C\) is:
\[
C = 2 \pi r
\]
Using \(r = 63\) and \(\pi = 3.14\):
\[
C = 2 \times 3.14 \times 63
= 6.28 \times 63
= 395.64
\]
So, the approximate circumference is **395.64**.

2. **Circumference of a circle with diameter 20:**

The formula for circumference is also:
\[
C = \pi d
\]
Using \(d = 20\):
\[
C = 3.14 \times 20
= 62.8
\]
So, the approximate circumference is **62.8**.

3. **Diameter from circumference of 574 meters:**

We can use the circumference formula to find diameter:
\[
C = \pi d \quad \Rightarrow \quad d = \frac{C}{\pi}
\]
Using \(C = 574\) and \(\pi = 3.14\):
\[
d = \frac{574}{3.14} \approx 183.29
\]
Rounded to the nearest tenth, the diameter is **183.3** meters.

4. **Circumference of a circle with radius 38 inches:**

Using the circumference formula:
\[
C = 2 \pi r
\]
Using \(r = 38\):
\[
C = 2 \times 3.14 \times 38
= 6.28 \times 38
= 238.64
\]
So, the approximate circumference is **238.64** inches.

5. **Area of a circle with radius 75 mm:**

The area \(A\) is calculated using the formula:
\[
A = \pi r^2
\]
Using \(r = 75\):
\[
A = 3.14 \times (75)^2
= 3.14 \times 5625
= 17625
\]
So, the approximate area is **17625.0** mm².

To sum up, here are the answers:

1. **395.64**
2. **62.8**
3. **183.3**
4. **238.64**
5. **17625.0**