## Sketch

### Area of a circle

**Formula**: Π * ^{r2} = A (area)

Π = 3.141592

Only 6 decimal places are shown for Pi here.

**Example calculation:** Pi (Π) * ^{5cm2} = 78.^{54cm2}

### Circumference of a circle

**Formula**: 2 * Π * r = U (circumference)

Π = 3.141592

Only 6 decimal places are displayed for Pi here.

**Example calculation:** (2 * Π) * 5cm = 31.4159265359cm (~ 31.42cm)

## How do you calculate the area of a circle?

To calculate the area of a circle, you need the formula A = πr². Where A is the area, π is the number of circles (approximately 3.14) and r is the radius of the circle. The radius is the distance from the center of the circle to the edge.

To apply the formula, you first need to know the radius of the circle. If you haven't given this directly, you can calculate it using the diameter (the distance from one edge to the other through the center): r = d/2.

Then simply insert the value for r into the formula and solve it. For example, a circle with a radius of 5 cm has an area of A = π x 5² ≈ 78.54 cm².

## How do you calculate the circumference of a circle?

The circumference of a circle is calculated using the formula U = 2πr. U stands for the circumference and r for the radius of the circle.

To apply the formula, you first need to know the radius of the circle. Then insert it into the formula and solve it. For example, a circle with a radius of 5 cm has a circumference of U = 2π x 5 ≈ 31.42 cm.

There is also an alternative formula for the circumference of a circle where you can use the diameter directly: U = πd. This formula results from the fact that the diameter d is exactly twice as long as the radius r.