1. Types of 3D Shapes Slideshow 42, Mathematics Mr Richard Sasaki Room 307

2. Objectives Learn some names and types of 3D shapes Learn some names and types of 3D shapes Understand the meaning of polyhedron and different types of polyhedron and prism Understand the meaning of polyhedron and different types of polyhedron and prism

3. Some Simple 3D Shapes SphereCubeCuboid Cylinder Cone Square-based pyramid Tetrahedron

4. Polyhedra What is a polyhedron? A polyhedron is a 3D shape with flat faces and straight edges. Vertex Edge Face A polyhedron is like, the 3D version of a polygon. Polyhedra (plural of polyhedron) can be concave or convex. This is. convex concave

5. Examples of Polyhedra So, which of the following are polyhedra? SphereCubeCuboid Cylinder Cone Square-based pyramid Tetrahedron

6. Regular Polyhedra What is a regular polyhedron? A regular polyhedron contains faces where all faces are. congruent polygons Note: The congruent polygons do not have to be regular. But they usually are. Angles do not need to be identical at all points. As long as the faces are polygons and are all congruent, the polyhedron is regular. Here, we can see all the faces are squares of the same size.

7. Convex Regular Polyhedra There are convex regular polyhedra. Tetrahedron Cube Octahedron Dodecahedron Icosahedron The names (except cube) refer to the number of faces each shape has.

8. Concave Regular Polyhedra There are concave regular polyhedra. Small Stellated Dodecahedron Great Dodecahedron Great Stellated Dodecahedron Great Icosahedron So altogether, there are 9 regular polyhedra.

9. Prisms A prism is a polyhedron with bases. Both bases are to one another. congruent This is a. pentagonal prism Prisms’ two bases are always to one another. parallel Is this a prism? No, it’s twisted. We call this an. antiprism