Construction Steps

Draw segment a = AB between points A and B Construct perpendicular line b to segment AB through point B Construct circle c with center B through point A Intersect circle c with perpendicular line b to get intersection point C Construct perpendicular line d to segment AB through point A Construct circle e with center A through point B Intersect perpendicular line d with circle e to get intersection point D Create polygon ABCD (Don’t forget to close the polygon by clicking on point A after selecting point D.) Hide circles and perpendicular lines Perform the drag test to check if your construction is correct