Euclidistan Flag

To create this flag, I used 2 pairs of parallel lines. The first set of parallel lines are line AB and line CD, each with a length of 10. The second set of parallel lines are line AC and line BD. Then, I made 3 isosceles right triangles, AFC, CFD, and BFD, with F, the midpoint of line AB, as a common vertex. Then I connected F to the midpoint of CD, which is E. This creates a bisector of the angle CFD. The measures of angles CAF, CFD, and FBD are 90 degrees. Since all the right triangles are isosceles, the remaining angles, angles ACF, AFC, FCE, FDE, BFD, and BDF, are all 45 degrees.