illustration

Given 4 corner coordinates.
I would like to divide the rectangle bounded by the 4 coordinates into 10 columns and 5 rows, which gives 50 grids. (red grid in the picture)
I would like to determine the coordinates of the corner of these 50 grids. (the green dots in the picture)
So, in the end, I should get 66 coordinates, 4 of which we already know.

I don’t know how to start, coordinates are not my strong point.