The diameter of a circle is 7.7 cms. What is the circumference of the circle ?

Options

A. 26.4 cms
B. 24.2 cms
C. 28.4 cms
D. 22.2 cms

Answer

To find the circumference of a circle when the diameter is given, follow these steps:

### Step 1: Identify the diameter
The diameter of the circle is given as 7.7 cm.

### Step 2: Calculate the radius
The radius (r) is half of the diameter.
\[ r = \frac{\text{Diameter}}{2} = \frac{7.7 \text{ cm}}{2} = 3.85 \text{ cm} \]

### Step 3: Use the formula for circumference
The formula for the circumference (C) of a circle is:
\[ C = 2 \pi r \]
where \(\pi\) is approximately 3.14.

### Step 4: Substitute the radius into the formula
Now, substitute the value of the radius into the formula:
\[ C = 2 \times 3.14 \times 3.85 \]

### Step 5: Perform the multiplication
Calculate the value:
\[ C = 2 \times 3.14 \times 3.85 = 24.178 \text{ cm} \]

### Step 6: Round the answer to one decimal place
To round 24.178 to one decimal place:
- Look at the second decimal place (7). Since it is 5 or greater, round up the first decimal place (1) by 1.
Thus, 24.178 rounded to one decimal place is 24.2 cm.

### Final Answer
The circumference of the circle is **24.2 cm**.

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