Here, we will see **program to find area of circle in go**. Given below, you can find algorithm and program.

Algorithm:

- You are given radius of circle.
- Calculate the area of circle using standard formula
- Return this result

**Area of a Circle Formula:**

`area_of_a_circle = pi * radius * radius`

```
Input :
a = 3
Output :
28.274334
Input :
a = 5
Output :
78.53982
```

**Code:**

```
package main
import (
"fmt"
"math"
)
func area_of_circle(radius int) float32 {
res := math.Pi * float32(radius) * float32(radius)
return res
}
func main() {
area := area_of_circle(3)
fmt.Println(area)
area = area_of_circle(5)
fmt.Println(area)
}
```

**Output:**

```
28.274334
78.53982
```

**To learn more about golang. Please follow given below link. **

https://techieindoor.com/go-lang/

**References:**

https://golang.org/doc/ https://golang.org/pkg/