The door frame is a hexagon, all sides are 59 cm.
Constructing a hexagon is easy:
Select the length of one side and draw it on flat surface or paper using straightedge, measuring tape.
Draw a straight line at one of the vertex which forms 60 degrees angle.
From this line turn 60 degrees and draw a line which is exact same length of the first side.
Or turn 120 degrees at one of the vertices of the first side, draw a line that is exact same length of the first side.
To make the frame out of steel pipes or to mix with wood, that’s the question.