> For the complete documentation index, see [llms.txt](https://hkust-robotics-team.gitbook.io/hkust-robotics-team-software-tutorial/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hkust-robotics-team.gitbook.io/hkust-robotics-team-software-tutorial/tutorial/tutorial-1-c-and-cubeide-setup/classwork/classwork-6-area-of-circle.md).

# Classwork 6 : Area of circle

Construct a function called `circleArea` to calculate the area of a circle using `float`s. Modify the following code:

```c
#include <stdio.h>
#include <stdbool.h>

// your function starts here
  
// your function ends here

int main() {
  printf("%f", circleArea(5.0f));
  return 0;
}
```