Q:

How to draw an isosceles trapezium with perpendicular diagonals

Can you explain me how to draw an isosceles trapezium with perpendicular diagonals? 
Thank you in advance!

A:

Start by drawing two perpendicular lines. Then draw two circles, with different radii, with centers at the intersection of the two lines. In the big circle choose two adjacent intersection with the two lines. On the small circle choose the intersections on the other side of the center. 

