3d stair; spiral stair
Vijay RebarVijay Rebar

Straight a straight staircase can be designed three different ways. the first design goes from top to bottom in a straight line. the second design is l shaped. it goes straight up and turns either right or left at a landing. the third makes a t; it goes straight up and turns both right and left from a landing. spiral a spiral staircase coils around on a fixed axis. often a pole from the floor to the ceiling and the stairs wraps around it.