 # Prisms Lesson 9-2.

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Prisms Lesson 9-2

2 Truths and a fib! A cylinder is not a polyhedron.
2. A cube is a type of pyramid. 3. A square pyramid has 5 faces.

What is a prism? A prism is a 3D figure with parallel bases
that are polygons. The other faces of a prism are parallelograms, most often rectangles. The name of a prism tells what the base should be shaped like: – Triangular prism – triangle bases – Rectangular prism – rectangle bases – Cube – square bases – Pentagonal prism – pentagon bases

The base has sides. 4 Vertices (points) 8 Edges (lines) 12
Rectangular Prism The base has sides. 4 Vertices (points) 8 Edges (lines) 12 Faces (planes) 6

Vertices (points) 6 Edges (lines) 9 Faces (planes) 5 Triangular Prism
The base has 3 sides. 5

The base has sides. 6 Vertices (points) 12 Edges (lines) 18
Hexagonal Prism The base has sides. 6 Vertices (points) 12 Edges (lines) 18 Faces (planes) 8

5 The base has sides. Vertices (points) 10 Edges (lines) 15
Pentagonal Prism The base has sides. 5 Vertices (points) 10 Edges (lines) 15 Faces (planes) 7

Name Picture Base Vertices Edges Faces
Triangular Prism Rectangular Prism Pentagonal Prism Hexagonal Prism Heptagonal Prism Octagonal Prism 3 6 9 5 4 8 12 6 5 10 15 7 6 12 18 8 Draw it 7 14 21 9 8 16 24 10 No picture Any Prism n 2n 3n n+2

Volume of a Prism = Bh where B = Area of the Base and h = Height of the Prism
Remember: the bases are the parallel sides and the height is the distance between the bases!!! Height of the prism Base

Volume of a Cube Volume= area of base x height V = Bh (B= AREA of the base) Side length is 5 inches Area of the base=? Height=? Volume= ? Area of the base=5(5) =25 Height=5 Volume= 125 cubic inches

Volume of a Rectangular Prism
V = area of base x height V = Bh (B= AREA of the base) 5 4 8 Area of base =? Height = ? Volume = ? Area of base =5 x 4 = 20 H = 8 V = 20 x 8 = 160

Triangular Prism Volume
6 8 5 10 4 Volume = Bh Volume = area of base x height Area of the base=? Triangle ½(6)(4) =12 Height of prism= ? Height of prism= 10 Volume= (12)10=120 cubic units

Go to the Notes to see another example
Go to the Notes to see another example! What do you say when you see an empty parrot cage? Poly-gon