This document is a lesson on calculating the volumes of pyramids and cones. It defines pyramids and cones, noting that pyramids are portions of prisms and cones are portions of cylinders. It provides the formulas for calculating the volume of a pyramid as 1/3 times the area of the base times the height, and the volume of a cone as 1/3 times pi times the radius squared times the height. It includes examples of calculating volumes of different shapes and poses questions for students to practice the concepts.

1. 12.5 Volume of Pyramids & Cones April 03, 2012
Bellwork
Get a cylinder and a prism from the back table.
Find the volume of each.
Put bellwork in homework bin.
HW pg. 832 #4­24 evens 1

2. 12.5 Volume of Pyramids & Cones April 03, 2012
12.5 Volume of Pyramids and Cones
Objectives:
1. To use the formulas for the volumes of pyramids & cones.
a
e of A pyramid is a portion of a prism.
volum ing the
the find ? A cone is a portion of a cylinder.
fin ding lar to m
is sim
i pris
ow d nd er/
H ami cyli
pyr
ne/ me of a
co
volu The relationship is 1/3.
HW pg. 832 #4­24 evens 2

3. 12.5 Volume of Pyramids & Cones April 03, 2012
Volume of a Pyramid:
Volume of a Cone:
V = 1/3 π r 2 h V = 1/3Bh
where B is the area of the base &
h is the height of the pyramid.
**Remember to use the perpendicular height**
HW pg. 832 #4­24 evens 3

4. 12.5 Volume of Pyramids & Cones April 03, 2012
Find the volume of the square
pyramid.
12 cm
7 cm
How much ice cream would be atop
a cone with a diameter of 2 in if
the ice cream is 3 inches high?
HW pg. 832 #4­24 evens 4

5. 12.5 Volume of Pyramids & Cones April 03, 2012
A trapezoidal pyramid has a
volume of 420 cubic yards. If
the height of the pyramid is 6
yards, what is the area of the
pyramid's base?
HW pg. 832 #4­24 evens 5

6. 12.5 Volume of Pyramids & Cones April 03, 2012
12.5 HW
pg. 832
#4-24 evens
HW pg. 832 #4­24 evens 6