How Many Triangles?
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Topics: Starter  Shape (3D)
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20
(or 40 if you count the reflection)
As the title suggests, the shape is a regular icosahedron, one of the five Platonic solids. It is a polyhedron composed of 20 triangular faces, with five meeting at each of the 12 vertices connected by 30 edges.
Can you sketch a net for this shape?
Have you seen the Great Dodacahedron?
Other shape counting starters:
How Many Squares 1?
 How Many Squares 2?
How Many Triangles 1?

How Many Triangles 2?  How Many Triangles 3?
How Many Rectangles?
 Rectangles Investigation 
Icosahedron
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