What is the purpose of a filename extension? how can you restore a file that you deleted from the hard disk?

The main purpose of the file name extension is that in the operating system it basically helpful for knowing the actual name of the file which we want to open in the system. The file name extension is also known as file suffix and file extension.

The file name extension are the character and gathering of the given characters after some time period that making the whole name of the record in the file system.

It basically enables a working framework, such as Windows and mac operating system (OS), figure out which programming on our PC the document is related with the particular file.

We can easily restore our file from hard disk system by two main ways as follows:

for this, you need the pythagorean theorem, which is a^{2}+ b^{2}= c^{2}

your a should be 12, and your b should be 35. so now you can solve for c, which equals 37 miles.

so the answer is 37 miles