Why we r using double in const double in data type

Question

constant double

Answer 1

Because you want to have a constant of type double within your program... ?

const double PI = 3.1415;

Answer 2

Did you go through the tutorials?

https://www.sololearn.com/learn/CPlusPlus/1622/?ref=app

Answer 3

what it actually mean double is it a decimal or an character what is its role could u plz tell me