PROGRAMMING:Area of circle
Input the radius of a circle , calculate the area. The result remain 2 digits after decimal point. (pi=3.1415)
### Input format:
A floating point data.
### Output format:
The output should be as follows, the instruction in the () is not the real output.
r = (radius value), area = (result)
### Input sample:
```
two point four
```
### Output sample:
```
r = 2.40, area = 18.10
```
answer：If there is no answer, please comment
### Input format:
A floating point data.
### Output format:
The output should be as follows, the instruction in the () is not the real output.
r = (radius value), area = (result)
### Input sample:
```
two point four
```
### Output sample:
```
r = 2.40, area = 18.10
```
answer：If there is no answer, please comment