Types of 3 D Shapes Slideshow 42 Mathematics
- Slides: 9
Types of 3 D Shapes Slideshow 42, Mathematics Mr Richard Sasaki
Objectives • Learn some names and types of 3 D shapes • Understand the meaning of polyhedron and different types of polyhedron and prism
Some Simple 3 D Shapes Sphere Cone Cuboid Square-based pyramid Cylinder Tetrahedron
Polyhedra What is a polyhedron? A polyhedron is a 3 D shape with flat faces and straight edges. Edge Face Vertex A polyhedron is like, the 3 D version of a polygon. Polyhedra (plural of polyhedron) can be concave or convex. This is . convex This is . concave
Examples of Polyhedra So, which of the following are polyhedra? Sphere Cone Cuboid Square-based pyramid Cylinder Tetrahedron
Regular Polyhedra What is a regular polyhedron? A regular polyhedron contains faces where all congruent polygons faces are . 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.
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.
Concave Regular Polyhedra There are concave regular polyhedra. Small Stellated Dodecahedron Great Icosahedron So altogether, there are 9 regular polyhedra.
Prisms A prism is a polyhedron with bases. congruent Both bases are to one another. pentagonal prism This is a . parallel Prisms’ two bases are always to one another. Is this a prism? No, it’s twisted and is connected by antiprism triangles. We call this an .
