Here is the pyramid model in both edit mode and object mode. To start, I actually created a plane and then set the X and Y to the correct scale. I then extruded the plane up on the Z axis to the assigned height. I proceeded to model the rest of the pyramid per the lesson.
Created ramp by deleting faces, and then extruding the edge at the top to the edge at the bottom and then merging them. Next, I used the knife tool to slice the ramp into sections. Then, I merged the vertices at the corners of the ramp’s sections. Lastly, I simply filled in the faces.