platonic talk-m-2

Slide 1:

Platonic Solids Family

Slide 2:

Hi, I am Hexahedron, you can call me Cube. Hi, I am Dodecahedron. Hi, I am Icosahedron . Hi, I am Tetrahedron. Hi, I am Octahedron.

Slide 3:

Tetrahedron Hexahedron ( cube ) Octahedron Dodecahedron Icosahedron

Tetrahedron:

Tetrahedron Faces are all equilateral triangles 4 vertices 6 edges 4 faces

Hexahedron:

Hexahedron Faces are all squares 8 vertices 12 edges 6 faces

Octahedron:

Octahedron Faces are all equilateral triangles 6 vertices 12 edges 8 faces

Dodecahedron:

Dodecahedron Faces are all pentagons 20 vertices 30 edges 12 faces

Icosahedron:

Icosahedron Faces are all equilateral triangles 12 vertices 30 edges 20 faces

Slide 9:

Platonic Solid Picture Number of Faces Shape of Faces Number of Faces at Each Vertex Number of Vertices Number of Edges Unfolded Polyhedron (Net) Tetrahedron 4 Equilateral Triangle ( 3-sided) 3 4 6 Cube 6 Square (4-sided) 3 8 12 Octahedron 8 Equilateral Triangle (3-sided) 4 6 12 Dodecahedron 12 Regular Pentagon (5-sided) 3 20 30 Icosahedron 20 Equilateral Triangle (3-sided) 5 12 30

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solid vertices Faces Edges Name Hexahedron 8 6 12 Octahedron 6 8 12 Dodecahedron 20 12 30 Tetrahedron 4 4 6

Slide 11:

Homework : Questions book: Exercises: (7, 8, and 9) Page 83

Slide 13:

There are only 5 Platonic solids. Platonic solids All the faces are congruent (same shape and same size). All the edges are equal in length. All the angles are equal in measure. A regular polygon has all its sides equal in length. The faces of a platonic solid are congruent regular polygons, with the same number of faces meeting at each vertex. The name of each solid is derived from the number of its faces.

Slide 14:

Tetrahedron Hexahedron Octahedron Dodecahedron Icosahedron Made of 4 equilateral triangles It has the smallest volume for its surface Made of 6 squares Commonly called a cube Made of 8 equilateral triangles It rotates freely when held by two opposite vertices Made of 12 equilateral pentagons Made of 20 equilateral triangles It has the largest volume for its surface area

Slide 15:

Platonic Solid Picture Nets of platonic solids Number of Faces Number of Vertices Number of Edges Tetrahedron 4 4 6 Hexahedron ( cube ) 6 8 12 Octahedron 8 6 12 Dodecahedron 12 20 30 Icosahedron 20 12 30