If you'd like to skip right to the beginning of the compass and straightedge process, go directly to step five. Do not pass "go" and do not collect $200. ;-)
(Note: I am aware that instructions for drawing a Penrose triangle have already been uploaded, but I chose to upload this anyway because I included compass and straightedge instructions.
Step 1: What You'll Need.
*Pencil and eraser
If you don't already have a compass, you can pick one up at your nearest Michael's craft shop.
Step 2: Step 1 (freehand)
Step 3: Step 2 (freehand)
Step 4: Step 3 (freehand)
Step 5: Step 1 (Compass)
Placing the stylus of the compass on one end of the line, draw an arc over the vicinity of the lines middle. Draw a second arc intersecting the first arc by placing the stylus on the opposite end. Then draw two lines from the original line's endpoints to the point where the arcs intersect. The result is an equilateral triangle.
Step 6: Step 2 (Compass)
After that, extend the lines of your triangle so that they touch the circle. For convenience in later steps, we will label the points where the lines touch the circle like so:
1.) The points on the top circle will be labeled A, B, C, and D.
2.) The points on the bottom-right circle will be labeled E, F, G, and H.
3.) The points on the bottom-left circle will be labeled I, J, K, and L.
Step 7: Step 3 (Compass)
*from point D to point K
*from point L to point I
*from point I to point F
*from point F to point E
Then erase as shown. It should end up like the second picture.
Step 8: Step 4 (Compass)
*from point L to point G
*from point E to point B
*from D to A
*from A to B
Again, erase so it looks like the second picture. (Forgive me for making this so repetitive!)
Step 9: Step 5 (Compass)
*a line from A to J
*a line from J to I
*a line from H to C
Once more, erase the lines as shown so that you end up with what's shown in the second picture. You can then get rid of all other unnecessary lines and labels to get the final result, shown in the third picture. Shade as you wish.
It's done! Hope you've enjoyed this 'Ible, despite its repetition. Please comment!