Trouble modelling a staircase

[Victor4]

Hello!

I would greatly appreciate any help. I have trouble modelling the staircase from the image. I can't figure out how to model the two triangular treads next to the landing.

Greetings

[Jeff Galbraith]

I'm not sure that's possible.  I'd have to play with the stair too.  Is that configuration compliant with building codes in your area?  I'm not sure that would be allowed where we practice.