 Hi, let's see how we can calculate and return the area of a circle. We know that we can find the area of a circle by using formula p times r squared. So in order to do that we need to use, to find area we need to use mathematical constant p. So if we want to use constant p we need to import math module because inside math module we have that constant p. We can call it by typing math dot p and here's the value of our p constant. Next what we want to do is to define function to calculate and return the area of a circle. So let's call our function with some descriptive name for example circle area for example and inside our function we need to put some arguments. We will put argument radius because we have formula p times r squared. So p is a constant value. We have it here and radius is a parameter that we want to get each time when we're working with our function. So now let's use that formula to find our area. Instead of p we're going to type math dot p times instead of r we're going to type radius and instead of radius squared we can write radius times radius or we have a shortcut for multiplying radius by itself and that is to use double asterisks operator and with this code we will get the same result that that is radius squared. We could put that inside parentheses for example so that our code will look more clear and the last thing that we want to do is to return our area. Okay that's it our function has been defined. Now let's try to calculate some area with our function. Let's find for example radius circle area of circle with radius 3 and we will get result 28.27 and so on. That's all in this lesson. Thanks for watching.