What is the area of a circle with diameter 8 cm?

The area of a circle with a diameter of 8 cm is 50.24 square centimetres.

To find the area of a circle, you need to use the formula \( A = \pi r^2 \), where \( A \) is the area, \( \pi \) (pi) is approximately 3.14, and \( r \) is the radius of the circle. The radius is half of the diameter. In this case, the diameter is 8 cm, so the radius \( r \) is \( \frac{8}{2} = 4 \) cm.

Now, substitute the radius into the formula:
\[ A = \pi r^2 \]
\[ A = \pi (4)^2 \]
\[ A = \pi \times 16 \]
\[ A = 3.14 \times 16 \]
\[ A = 50.24 \]

So, the area of the circle is 50.24 square centimetres. This method can be used for any circle as long as you know the diameter or the radius. Remember, the key steps are to find the radius first if you are given the diameter, and then apply the area formula. This is a fundamental concept in geometry and is very useful in various real-life applications, such as designing circular objects or spaces.