Day 3: Basic Circle Calculator

My third day of learning C. I wrote this simple program to practice how to use the math.h library and handle user input.

What it does:

The program takes a radius value from the user and calculates:

Area of a circle Circumference of a circle Surface area of a sphere Volume of a sphere

How I built it:

Used double for precision. Added a basic if check to prevent negative radius inputs. Used pow() for calculations. Note for Linux users: Compile with -lm to link the math library.