Click on all the shapes that can be created by cutting a rectangular pyramid perpendicular to its base. A. pentagon B. rectangle C. square D. trapezoid E. triangle

The correct answers are **B. rectangle, C. square, and D. trapezoid.**<br /><br />Here's why:<br /><br />* **Rectangle/Square:** If the cut is parallel to the base, the resulting shape will be a rectangle. If the rectangular pyramid is a *square* pyramid, and the cut is parallel to the base, the resulting shape will be a square.<br /><br />* **Trapezoid:** If the cut is not parallel to the base, but still perpendicular to it, the resulting shape will be a trapezoid. Imagine tilting the cutting plane – the sides that were parallel in the rectangle now slant inwards or outwards, creating a trapezoid.<br /><br />* **Why not Pentagon or Triangle:** A cross-section perpendicular to the base will always have four sides (or fewer if the cut goes through a vertex). A pentagon has five sides, and a triangle has three, so these are impossible to create with this type of cut.<br />