In this lesson, we'll learn how to write programs to draw circles on the canvas.
Simple Circle
We'll start with drawing a circle. This involves two steps, creating a circle and showing it.
c = circle()
show(c)
The first line creates a circle shape and the secone line shows it.
Just like the print function is used to display numbers and strings,
the show function is used to display shapes.
Controlling the Size
The size of the circle is controlled by its radius. By default, the
radius of the circle will be 100, but we can specify a different value
for the radius. The is done by setting the parameter r.
c = circle(r=50)
show(c)
Try making the circle bigger by changing the value of parameter r.
!!! note 'Named and positional arguments'
You may have noticed that we are using the `circle` and
the `show` functions very differently.
We are calling the `show` function as `show(c)`, but the `circle`
function as `circle(r=50)` and not as `circle(50)`.
In Python, it is possible to pass arguments by name (like r=50, x=10 etc)
and by position (like in `print(1, 2, 3)`).
It is too early for us to get into those details. For now, just understand
that both these ways are acceptible.
More Circles
We can also create more than one circle. The following example draws
two conentric circles with radius 50 and 100.
c1 = circle(r=50)
show(c1)
c2 = circle(r=100)
show(c2)
Just like print, the show function also supports taking multiple
arguments and we can use that to show multiple shapes at once.
c1 = circle(r=50)
c2 = circle(r=100)
show(c1, c2)
Exercise 2.1: Three Concentric Circles
Draw three concentric circles with radius 50, 100 and 150 respectively.
