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Lesson Plan #86
Date: Tuesday April 23rd, 2013
Class: Geometry
Topic: Prisms
Aim: How do we find the volume of a prism?
Objectives:
1) Students will be able to find the volume of a prism.
2) Students will be able to find the surface area of a prism
HW # 86:
Page 478 #’s 17-22
Do Now:
Find the area of the regular hexagon with a side
of length 4.
Assignment #1:
List properties of the figure at right?
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Give Back HW
Collect HW
Go over the Do Now
What name do you give to the figure at right?
Definition: A prism is a solid that has two faces that are parallel and congruent. These are called the bases of the
prism. If you take a cross section of a prism parallel to those bases, the cross section will look just like the bases
(congruent to them).
Prisms are named for the shape of the base, and whether they are right vs. oblique.
A right prism is one where the bases are exactly one above the other. This means
that lines joining corresponding points on each base are perpendicular to the bases.
Question:
Which of the following figures is a right prism?
A) Figure 1
B) Figure 2
C) Figure 3
D) Figure 4
Parts of a prism: http://www.learner.org/interactives/geometry/3d_prisms.html
Different Types of Prisms:
Triangular Prism
Square Prism
Rectangular Prism
Pentagonal Prism
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Question:
An octagonal prism has ____.
A. one vertex
C. six congruent lateral faces
B. eight congruent faces and one base
D. eight lateral faces that are congruent
Let’s see how we can find the volume of prism.
Question:
What is the volume of a prism whose ends have an area of 25 in2 and which is 12 in
long?
Question: The diagram shows a prism whose cross-section is a right triangle. What is the volume
of the prism?
Question: The diagram shows a prism whose cross-section is an isosceles trapezoid. What is the
volume of the prism?
Example 1:
Find the lateral surface area (not including
the area of the bases) of a triangular prism
with bases edges 3 inches, 4 inches and 5
inches and altitude 8 inches.
Example 2:
Find the total surface area of an isosceles
trapezoidal prism with parallel edges of the
base 6 cm and 12 cm, the legs of the base
5 cm each, the altitude of the base 4 cm
and height of the prism 10 cm.
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Example 3:
Example 5:
Example 6:
Example #7:
Example 4:
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Example #8:
Example #9:
Example #10:
Example #11:
Example #12: