D. Rectangle
It will be smaller than the base
If you cannot read it, let me know.
The shape of the cross section is a triangle. Therefore, the answer is the second option: Triangle.
A rectangular pyramid is a pyramid that has a rectangle as its base. Therefore, its base has four sides. The rectangular pyramid also has four triangles that coming together in its apex. So, if the rectangular pyramid is<span> sliced so the cross section is perpendicular to its base and passes through its vertex, the cross section obtained is a triangle.</span>
