Here's how we can do that:
Create a type declaration file for your project. In this file, you need to have all the type, function, modules declarations. We keep these declarations in a special type of file which has .d.ts extension.
/// <reference path='math.d.ts' />
Now we can see we have type suggestions for our code.
Note: This can only help in giving suggestions as per our type declarations and will not enforce you to write strictly typed code. For example: If I try to read any other property than available ones' on circleDetails, it won't restrict me in doing so, which is the case in TypeScript.