The radius of a circle is 4cm. What will be its diameter?

Answer

To find the diameter of a circle when the radius is given, you can follow these steps:

### Step-by-Step Solution:

1. **Identify the given information**:
- The radius of the circle is given as 4 cm.

2. **Recall the formula for diameter**:
- The diameter (D) of a circle is twice the radius (r). The formula is:
\[ D = 2 \times r \]

3. **Substitute the value of the radius into the formula**:
- Here, the radius (r) is 4 cm. So, we substitute:
\[ D = 2 \times 4 \text{ cm} \]

4. **Calculate the diameter**:
- Now, perform the multiplication:
\[ D = 8 \text{ cm} \]

5. **State the final answer**:
- Therefore, the diameter of the circle is 8 cm.