1. Prisms Lesson 8-2

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.

3. 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

4. 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

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

6. 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

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

8. 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

10. 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

11. 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

12. 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

13. Triangular Prism Volume6 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

14. Recall the concept of density, so we can apply this to real life problems.
A big theater in New York has 1.3 million square feet. At the last show a band named Flaming Bananas surveyed the theater to make sure there wasn’t overcrowding. They found the population density to be people per square foot. This included all people in the building.
How many total people attended the theater on that day?

15. Julia runs a hotel. She wants to hold a party in the banquet hall of her hotel. The hall has a size of 70,000 square feet. She found the population density to people per square foot. This included all people in the banquet hall.
How many total people can attend the party in banquet hall?
280 people

16. Look at cross-sections of a cube. Suppose a plane intersects a cube.
Describe the different cross sections when a plane intersects a cube.
Bryant says that it’s not possible to form a circle or an octagon as a cross section of a cube. Is Bryant correct? Explain your reasoning.

17. A rectangle What do you call a broken angle?
Now try the “summer is coming soon” problem.

18. 9900
=330(30)=9900 or 20
37.5
.625(60)=37.5