What is the area of the hotel stairwell?

1 step width should not be less than 0.28m, step height should not be greater than 0. 16m, and continuous steps should not exceed the level of 18. If it exceeds the level of 18, an intermediate rest platform should be added, and the width of stair platform should not be less than the flight width and1./kloc-0.

2 spiral stairs are not allowed. When fan-shaped stairs are used, the width of the stairs at the horizontal distance of 0.25m from the handrail at the narrow end of the stairs should not be less than 0.22m, the handrail at the wide end should not be greater than 0.50m, and the narrow end of the rest platform should not be less than1.20m.: ：