# Golang math.Phi Constant with Examples

Golang | math.Phi Constant: Here, we are going to learn about Phi constant of the math package with its usages, syntax, and examples.
Submitted by IncludeHelp, on August 24, 2021

## math.Phi Constant

The Phi constant is an inbuilt constant of the math package which is used to get the value of mathematical constant φ (Golden Ratio). The number φ also called the golden ratio, turns up frequently in geometry, particularly in figures with pentagonal symmetry. Indeed, the length of a regular pentagon's diagonal is φ times its side.

Syntax:

```float64 math.Phi
```

Parameter(s):

• None

Return Value:

The return type of math.Phi constant is float64, it returns the value of mathematical constant φ.

Example 1:

```// Golang program to demonstrate the
// example of math.Phi Constant

package main

import (
"fmt"
"math"
)

func main() {
fmt.Printf("Type of math.Phi is %T\n", math.Phi)
fmt.Println("Value of math.Phi:", math.Phi)
}
```

Output:

```Type of math.Phi is float64
Value of math.Phi: 1.618033988749895
```

Explanation:

In the above program, we imported the math package to use the math.Phi constant then printed the type and value of the math.Phi constant.

Example 2:

```// Golang program to demonstrate the
// example of math.Phi Constant

package main

import (
"fmt"
"math"
)

// creating function to return
// the value of Phi.
func getPhi() float64 {
return math.Phi
}

func main() {
fmt.Println("Value of math.Phi:", getPhi())
}
```

Output:

```Value of math.Phi: 1.618033988749895
```