side view

front view

Top view

Drawing the bowstring

The drawing stages

Match formula facilities
Sufficient depth of step
Convenient staircase inclination 39.8°
Comfortable ladder

Initial data
The height of the stairs 2500 mm
The length of the stairwells in the plan 3000 mm
Number of steps 13
The thickness of the steps 50 mm
Ledge steps 50 mm

The length of the bowstring 4167 mm
The angle of the stairs 39.8°

Step size
Step height 192 mm
Depth steps 281 mm
The height of risers 142 mm