Radians are a way to measure angles. You know how we measure angles in degrees, like 90 degrees or 180 degrees? Well, radians are just another way to measure angles.
So, imagine you have a circle. When you draw a line from the center of the circle to the edge, you create an angle. If you measure that angle in degrees, a full circle would be 360 degrees. But if you measure that same angle in radians, a full circle would be 2π radians.
You might be wondering, "What's π?" Well, π is a special number that's about 3.14. It's actually an irrational number, which means it goes on forever without repeating. But we use it a lot in math, especially when we're talking about circles and angles.
Now, let's say you want to measure an angle in radians. Instead of using degrees, you would use the symbol "r" after the number. For example, if you had an angle of 45 degrees, that would be π/4 radians. If you had an angle of 90 degrees, that would be π/2 radians.
So, in short, radians are just another way to measure angles, and they're especially useful when we're talking about circles and things that go around in circles.