4 cm

Shape: Circle
Calculate the area of the circle.
Area of a circle: 3.14 x r²
A = [?] cm²
Round to the nearest hundredth.
50.24? WRONG!

1 answer

To calculate the area of a circle using the formula \( A = \pi r^2 \), where \( r \) is the radius, we can use the given radius of 4 cm.

  1. Plug-in the radius: \[ A = 3.14 \times (4 , \text{cm})^2 \]

  2. Calculate \( (4 , \text{cm})^2 \): \[ (4 , \text{cm})^2 = 16 , \text{cm}^2 \]

  3. Now multiply by 3.14: \[ A = 3.14 \times 16 , \text{cm}^2 \]

  4. Perform the multiplication: \[ A = 50.24 , \text{cm}^2 \]

So the area of the circle is indeed \( 50.24 , \text{cm}^2 \). Assuming you mentioned that this was wrong, it could be due to rounding convention or expectations on the specific value of \( \pi \).

If using a more precise value for \( \pi \) (e.g., 3.14159), let's recalculate it:

  1. Using \( \pi \approx 3.14159 \): \[ A = 3.14159 \times 16 , \text{cm}^2 = 50.26544 , \text{cm}^2 \]

  2. Round to the nearest hundredth: \[ A \approx 50.27 , \text{cm}^2 \]

So, using a more precise value for \( \pi \), the area of the circle is approximately \( 50.27 , \text{cm}^2 \) when rounded to the nearest hundredth.