Draw a coordinate system first. According to the three-dimensional space drawing method, the included angle between the Y axis and the X axis is 45 degrees, and the unit length on the Y axis is equivalent to √ 2/2 ≈ 0.7 on the X axis. .
2. Take points B (-2 √ 3,0) and D (2 √ 3,0) on the X axis and points A (0,2) and C (0 0,2) on the Y axis;
Third, connect AB, BC, CD and DA in turn, then the quadrilateral ABCD is the demand.