In a previous lesson, you learned how to use the

`mouse()`

function to
draw lines between two mouse click positions. Let's keep going and see if can draw circles with the
mouse. How about we'll use the first click as the center of the circle, and the second click
as a point through which the circle should pass?
Remember that drawing a circle takes three numbers, as outlined in this lesson. The first two are the $(x,y)$
coordinate of the center of the circle. The third number is the radius of the circle. Since the second click position should be on the circle, the radius
of the circle should be *the distance* between the two mouse-click points. Ah ha! A chance to use the distance formula.

Type your code here:

See your results here:

This code will not run. You have to fix the

`d=sqrt( )`

line to compute the distance
between the two mouse-click points, $(x_1,y_1)$ and $(x_2,y_2)$. Next, you have to
complete the `circle( )`

line to properly draw the circle centered at $(x_1,y_1)$ with
a radius of $d$. Can you do it?
Dismiss.
Does your code work? Want to run it on your iPhone?

Here's your code:

- Use [Control]-[C] (Windows) or [⌘]-[C] (MacOS) to copy your code.
- Paste it using [Control]-[V] (Windows) or [⌘]-[V] (MacOS) into
this page
- Then click the "Use on iPhone" button that you'll see.