Slicing 3D Shapes

Cross Sections 2020

 Describe the two-dimensional figures (cross sections) that result from slicing three-dimensional figures, as in plane sections of right rectangular prisms, right rectangular pyramids, cones, cylinders, and spheres. 

Cross Sections

• •What are cross sections?

  
  

  •What plane figures can I make by slicing a cube by planes?

  
  

  What about when I slice cones, prisms, cylinders, and pyramids instead of cubes

Multiple Choice

What is a cross section?

• 2- dimensional view of a 3-D shape

• 3-D view of a 2-dimensional shape

• 2- dimensional view of a 2-D shape

3 types of slices you will see

A left to right slice is parallel to the base.

An up and down slice is perpendicular to the base.

A diagonal slice is at an angle.

Horizontal (Parallel) to the base

This will always give you the shape of the base!

Vertical (Perpendicular)

This will always give you the shape of the face

Multiple Choice

If you slice a shape parallel to the base, what will the cross section be the shape of?

• face

• base

• stretched base

Cylinders

parallel gives you a circle

perpendicular gives you a rectangle

Multiple Choice

If you slice a shape perpendicular to the base (vertical), what will the shape always be?

• face

• base

• fase

• bace

Multiple Choice

• cone

• rectangle

• square

• triangle

Rectangular Pyramids

• perpendicular (vertical) gives you a triangle

• parallel gives you a rectangle

Multiple Choice

• a circle

• cycloid

• parabola

• hyperbola

Triangular Prisms

parallel gives you the shape of the base, which is a triangle

perpendicular to the base would give you a rectangle

Multiple Choice

• pyramid

• prism

• square

• triangle

Cones

parallel=circle

perpendicular=triangle

Spheres

Circle no matter how you slice it

Special

If you slice a square pyramid without going through the top (Vertex) you will get a trapezoid

Angled slices

will give you a stretched out base

Practice

Answers

Interactive

_{https://www.geogebra.org/m/XCZwsytr}