# Practice with Random numbers using graphics

Make a graphics display that looks like the following:

• set the background colour to something (I made it a pale yellow, but it doesn't matter).
• Set the top quarter of the screen to be a grey rectangle (filled in).
• Set the bottom quarter of the screen to be a pink rectangle.

Now do the following

Make a random x and random y for the gray square

Use Math.random() → select the colour: We want a 30% chance that the dot is white and a 70% chance that it is black.

Draw the dot in the top left quadrant. I just used `gc.fillRect(x,y,2,2)`

And for the bottom right quadrant...

Make a random x and random y for the coordinates that go into the pink square

Make a random number that is a 1,2, or 3.

Use a switch statement to make the colour be red, green, or blue, depending on the random number

Get another random integer for the circle size. This number should be between 5 and 35.

Draw the circle

Wrap the whole thing in a while loop (well, not the setup section), and it should end up looking like this:

FYI: You actually only need 3 variables, aside from variables to set the window width and height

Gray square: x,y
Pink square: you can reuse x and y since there is no reason not to.
Then you need one more variable, r, for the random number 1, 2 or 3.
After you've set the colour to be red, green, or blue, you can then reuse "r" for the size of the circGle.

It's good to reuse variables, but only if it make sense and doesn't make the program confusing to read.

So don't feel that you have to limit yourself to 3 variables. Use more if it makes sense to you.

If you want, do something interesting with random numbers & graphics in one of the other two quadrants

### Marking

* coding techniques
* elegance
* does it still work perfectly if you set WINW and WINH to different values