Turning and drawing

Let's learn more about turning and drawing! Try writing:

Now the turtle will walk like this:

Why like that? First he walks 100 steps forward. Then we tell him RT 90. RT tells him we want him to turn right. The number tells him how much we want him to turn. He doesn't draw anything when he turns. After that he walks 100 step forward again.

Why 90 and not some other number? A long time ago humans decided that a full turn should be 360 degrees. A half turn was 180 degrees. That is when you turn around and face the other way. A quarter turn was 90 degrees. (A quarter is half of a half.) The turtle knows this. These are important numbers we will keep meeting. (But sometimes we want to use other numbers too!)

How do you know what to tell the turtle when you want him to draw? Put yourself in his shoes. Pretend that you are a turtle. Then tell yourself how to walk. Think Turtle -- think like a turtle.

The turtle draws.

Let's try it! How would you walk to draw a square? Think about that. Then write it on paper. Now type it in. It doesn't matter if you don't get it right the first time. Most people don't, and you can change it as many times as you want. The turtle is your friend. He is very patient!

Want to draw a house? Write it down, then type it in. Try drawing a taller house. Or a longer house. Try drawing a boat. Then a longer boat. Or something else that you want to draw.

Here are some more Logo words. You can say these words to the turtle and he will understand:

Logo word	What it means
FD 100	Walk forward 100 steps
BK 100	Walk backward 100 steps
LT 90	Turn left (good for drawing squares)
RT 90	Turn right (good for drawing squares)
LT 120	Turn left (good for drawing triangles)
RT 120	Turn right (good for drawing triangles)
CS	Remove everything you have drawn
HOME	Move back to the starting point (and draw a line)
PU	Lift the pen so you won't draw when you walk
PD	Put the pen towards the screen again

Some of them we have already talked about. Others are new. Go ahead and play with them. You don't have to use all of them. Use the ones you think seem fun.

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