Ernie....
The second and third step are both 9 3/4" x 29 1/4"
The first step (closest to the door) is 6 1/2" x 29 1/4"
On all the steps, their width is 29 1/4". On the three steps, there is an arch cut in the tile on both sides so the step lifts up. On the first step, the majority of it is 29 1/4" wide, but near the door, where they didn't cut the arch, it's only 28 1/2", so there's a 1" jog.
We had carpets made for the second and third steps, the triangle in front of the passenger seat and one in front of the driver's seat. We had rubber backing added and then bound. We did this on our last coach and they were still in good shape after 5 years.
We cut our step mats to 28" x 9".
In the second photo you can see in the lower left corner where the first step is 1" narrower near the door.