Write a Logo procedure one called "start" which clears the screen and draws a green line in the direction the turtle is facing, returning the turtle to its initial position.

Write a second procedure called "turn" which takes one argment, :angle. This prodecure should rotates the turtle through the given angle, draw a red line in the direction the turtle then faces, and return the turtle to the origin. The turtle's total turn after doing this should be :angle.

Find a partner. Enter "start" and then "turn" with some angle. Ask your partner to enter "turn" and the angle needed to complete a one hundred and eighty degree turn. The final result should be two collinear segments (drawn by "start" and the second "turn" command) and one segment at the angle chosen by the first player. Then let your partner choose an angle and find its complement yourself. After one or two games like this, shrink the Logo input window so that all you can see is one line of text and play again.