Circumference Practice Problems - Circle Perimeter Worksheets

To solve this problem, we will determine the circumference of the circle:

• Step 1: Identify the radius, $r$. From the diagram, the number $4$ is provided, suggesting that $r = 4$ cm.
• Step 2: Use the circumference formula for a circle: $C = 2\pi r$.
• Step 3: Substitute the radius into the formula: $C = 2\pi \times 4 = 8\pi$ cm.

Therefore, the circumference of the circle is $8\pi$ cm. This aligns with choice 3 from the provided options.

The correct and verified circumference is $8\pi$ cm.

To solve the problem of finding the circumference of a circle with radius $r = 7$, we will follow these steps:

• Step 1: Identify the given value of the radius.
• Step 2: Apply the formula for the circumference of a circle.
• Step 3: Calculate the result using known values.

Let's go through these steps in detail:

Step 1: The radius $r$ is given as $7$.

Step 2: The formula for the circumference of a circle is $C = 2\pi r$.

Step 3: Substitute the given radius into the formula:
$C = 2\pi \times 7 = 14\pi$

Using the value of $\pi \approx 3.14159$, we can calculate:

$C \approx 14 \times 3.14159 \approx 43.982$

Therefore, the circumference of the circle is approximately $43.982$.

To solve this problem, follow these steps:

• Step 1: Given that the radius $r = 6$.
• Step 2: Use the formula for the circumference of a circle, $C = 2\pi r$.
• Step 3: Substitute the radius into the formula: $C = 2\pi \times 6$.
• Step 4: Calculate the expression: $C = 12\pi$.
• Step 5: Approximate $\pi \approx 3.14159$ to find $C \approx 12 \times 3.14159$.
• Step 6: Perform the multiplication: $C \approx 37.69908$.
• Step 7: Round off the number to three decimal places: $C \approx 37.699$.

The correct answer matches the choice labeled 2: 37.699.

To solve this problem, we'll follow these steps:

• Step 1: Identify the given information
• Step 2: Apply the appropriate formula
• Step 3: Perform the necessary calculations

Now, let's work through each step:
Step 1: The problem provides the radius of the circle as $r = 11$.
Step 2: We'll use the formula for the circumference of a circle: $C = 2\pi r$.
Step 3: Plugging in the value of the radius, $r = 11$, into the formula, we get: $C = 2\pi \times 11 = 22\pi$.
Using approximately $\pi = 3.14159$, we calculate: $C = 22 \times 3.14159 \approx 69.115$.

Therefore, the circumference of the circle is approximately 69.115.

Upon comparing this with the given choices, the correct choice is:
Choice 4:

69.115

The formula for the circumference is equal to:

$2\pi r$