Transcript PA Lesson 11-3

Lesson 11-3 Pages 568-572
Volume: Pyramids and
Cones
What you will learn!
1. How to find volume of
pyramids.
2. How to find volume of
cones.
Cone
What you really need to know!
To find the volume V of
a pyramid, use the
formula V = 1/3 Bh,
where B is the area of
the base, and h is the
height of the solid.
What you really need to know!
To find the volume V of
a cone, use the formula
2
V = 1/3 r h, where r is
the radius of the base,
and h is the height of
the solid.
Link to Pre-Made Lesson
Example 1:
Find the volume of the
pyramid. If necessary,
round to the nearest tenth.
1
V  Bh
3
1
V  15 15 12
3
V  900in
3
Example 2:
Find the volume of the
pyramid. If necessary,
round to the nearest tenth.
1
V  Bh
3
Base are 19
2
cm
Height 21 cm
1
V  19  21
3
Base are 19
2
cm
Height 21 cm
V  133cm
3
Base are 19
2
cm
Height 21 cm
Example 3:
Find the volume of the
cone. If necessary, round
to the nearest tenth.
1 2
V  r h
3
Example 3:
Find the volume of the
cone. If necessary, round
to the nearest tenth.
1
2
V    5.5  8
3
Example 3:
Find the volume of the
cone. If necessary, round
to the nearest tenth.
V  253.4m
3
Example 4:
When mulch was dumped
from a truck, it formed a
cone-shaped mound with a
diameter of 15 feet and a
height of 8 feet. What is the
volume of the mulch? Round
to the nearest whole number.
1 2
V  r h
3
1
2
V    7.5  8
3
V  471 ft
3
Example 4b:
How many square feet
can be covered with this
mulch if 1 cubic foot
covers 4 square feet of
ground?
4 x 471 = 1,884
2
ft
Page 570
Guided Practice
#’s 4-9
Read:
Pages 568-570 with
someone at home and
study examples!
Homework: Pages 571-572
#’s 10-23, 27-34
Practice Quiz 1 #’s 1-5
Page
751
Lesson 11-3