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Learning Math Home
Session 9: Solids
 
Session 9 Part A Part B Part C Homework
 
Glossary
geometry Site Map
Session 9 Materials:
Notes
Solutions
Video

Session 9, Part A:
Platonic Solids (45 minutes)

In This Part: Building the Solids | Naming the Solids

Platonic solids have the following characteristics:

 

All of the faces are congruent regular polygons.

 

At each vertex, the same number of regular polygons meet.

In order to do the following problems, you will need Polydrons or other snap-together regular polygons. If you don't have access to them, print this Shapes PDF document as a template for cutting shapes out of stiff paper or poster board.

Problem A1

Solution  

a. 

Connect three triangles together around a vertex. Complete the solid so that each vertex is the same. What do you notice? Were you able to build a solid?

b. 

Repeat the process with four triangles around a vertex, then five, then six, and so on. What do you notice?


 

Problem A2

Solution  

a. 

Connect three squares together around a vertex. Complete the solid so that each vertex is the same. What do you notice? Were you able to build a solid?

b. 

Repeat the process with four squares around a vertex, then five, and so on. What do you notice?


 

Problem A3

Solution  

a. 

Connect three pentagons together around a vertex. Complete the solid so that each vertex is the same. What do you notice? Were you able to build a solid?

b. 

Repeat the process with four pentagons, then five, and so on. What do you notice?


 

Problem A4

Solution  

Connect three hexagons together around a vertex. Complete the solid so that each vertex is the same. What do you notice? Were you able to build a solid?


 

Problem A5

Solution  

How many Platonic solids are there? Explain why that's the case.


Next > Part A (Continued): Naming the Solids

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