## Explanation

In geometry, the area enclosed by a circle with radius (r) is defined by the following formula: πr^{2}

The Greek letter π ("pi") represents the ratio of the circumference of a circle to its diameter. In Excel, π is represented in a formula with the PI function, which returns the number 3.14159265358979, accurate to 15 digits:

```
=PI() // returns 3.14159265358979
```

To square a number in Excel, you can use the exponentiation operator (^):

```
=A1^2
```

Or, you can use the POWER function:

```
=POWER(A1,2)
```

Rewriting the formula =πr2 as an Excel formula to for the example, we get:

```
=PI()*B5^2
```

Or:

```
=PI()*POWER(B5,2)
```

The result is the same for both formulas. Following Excel's order of operations, exponentiation will occur before multiplication.