1. Generate side lengths
• Click on the New Dimensions button (and wait 2 secs).
REMEMBER: You can always click on 
(top right) to undo your last action.
2. Make the base of your rectangle.
• Click on 
"Segment with given length from point" icon.
• Then click on the point A (it will glow) and In the box type the number of the base of your rectangle. Hit Enter.
3. A rectangle has a 90° angle with its base.
• Click on 
"Angle with given size" icon.
• Click on point B, then on point A and erase 45 and type in 90. Leave the °! Hit Enter. (If you erase the degree sign, you can get another by clicking on the arrow to the right of 
.
4. Draw a line through A and C.
• Click on 
"Line through 2 points" icon.
• Click on A and then C.
5. Now we need the point on this line that is the height of the rectangle so we draw a circle with center A and radius the height of the rectangle. The intersection between the circle and the line is the point we need.
• Click on 
"Circle with center and radius" icon. Click on A and then type in the value of the height of your rectangle.
• Click on 
"Intersect two objects" icon and then click on the line circle
6. Now do 3-5 on the top side of your rectangle.
• Click on , then on A and then on D. Erase 45 and type in 90. Leave the °. Hit Enter.
• Click on , then on D and then on E.
• Click on , then on D and type in base number.
• Click on then on linecircle.
7. Close your rectangle ADFB.
• Click on 
"Segment between two points" icon. Click on A and D. Click on D and then on F. Click on F and then on B.
8. Clean up
9. Play with your rectangle.
• Click and drag any blue point (A moves the rectangle, B rotates the rectangle). Notice that the rectangle itself never changes since it is completely defined by the length of the two sides and the 90° angles.
• Click on Reset to start over.