Find the circumference of a circle using the formula C=πd

Question

if the circle's diameter is 3.75 feet. Use the 3.14 for π
.

*Be sure to round correctly!

Hint: On the rounding, watch that you are rounding each place value correctly. Also, set this problem up as an equation and use the values given to replace the parts of the equation in order to find the answer.

(1 point)
Responses

12 ft
12 ft

11.78 ft
11.78 ft

44.18 ft
44.18 ft
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Answer 1

To find the circumference \( C \) of a circle using the formula \( C = \pi d \), we will replace \( \pi \) with 3.14 and \( d \) with 3.75 feet.

Step 1: Set up the equation

\[ C = \pi d \] Substituting the values: \[ C = 3.14 \times 3.75 \]

Step 2: Perform the multiplication

Now, calculate \( 3.14 \times 3.75 \): \[ C = 3.14 \times 3.75 = 11.775 \]

Step 3: Round the result

Now we need to round 11.775. The common rounding rules state:

• If the digit after the desired place (the third decimal place here: 11.775 → 11.78) is 5 or higher, round up.

Since the digit in the third decimal place (5) is equal to 5, we round the second decimal place (7) up to 8. Thus, \[ C \approx 11.78 \text{ feet} \]

Conclusion

Therefore, the circumference of the circle is approximately 11.78 ft.