Religion: http://mrlafrossia.blogspot.com/
Math: page 233 Progress #1-9
Slice Three-Dimensional Figures
A geometric plane is a two dimensional figure that goes on and on in both directions without end. Think of it as sheet of paper that never ends. The two dimensional figure that is made by slicing through a three dimensional figure using a plane is called a plane section or a cross section..
Parallel planes are planes that do not intersect. Think of the floor and ceiling of a room as parallel planes.
Perpendicular planes are planes that meet at right angles. Think of the floor and a wall of a room as perpendicular planes.
A right rectangular pyramid is a three dimensional figure that has a rectangular base and three triangular faces that meet at a view called the vertex. That vertex is positioned exactly above the center of the base.
When a geometric plane slices any right pyramid so that the cut is parallel to the plane of the base, the cross section will have the same shape (but not exactly the same size) as the base. So, in case of a right rectangular pyramid, the cross section is a triangle.
If the cut is perpendicular to the base but does not passes through the vertex, the cross section will be a trapezoid.
