Embed Size (px)
Citation preview
112 Surface Areas of Prisms and Cylinders 2011
1
March 24, 2011
Objective
Find the surface area of prisms and cylinders.
112 Surface Area of Prisms and Cylinders
112 Surface Areas of Prisms and Cylinders 2011
2
March 24, 2011
PrismWhat is a solid?
A solid is a three‐dimensional
shape.
PyramidCylinder Cone
What is a prism?A prism is a solid that has two congruent bases.
112 Surface Areas of Prisms and Cylinders 2011
3
March 24, 2011
PrismA prism is a solid that has two
congruent bases.Congruent means "same size and
same shape".The base of a prism can be any shape. You name a prism by the shape of its base.This prism has two square bases and four rectangular faces.
112 Surface Areas of Prisms and Cylinders 2011
4
March 24, 2011
112 Surface Areas of Prisms and Cylinders 2011
5
March 24, 2011
Examples of Prisms
Prism with two circular bases (Cylinder)
Prism with two pentagonal bases and 5 rectangular faces
112 Surface Areas of Prisms and Cylinders 2011
6
March 24, 2011
So, how do we find the surface area of a prism?
First, "unfold" the prism so that all the surfaces lie flat. This is called
making a "net".
112 Surface Areas of Prisms and Cylinders 2011
7
March 24, 2011
Solid Net
112 Surface Areas of Prisms and Cylinders 2011
8
March 24, 2011
Now, find the area of all the separate pieces and add them
together.
Area of a prism = Area of 2 bases + Area of all faces
112 Surface Areas of Prisms and Cylinders 2011
9
March 24, 2011
Solid Net
15 in.
6 in.
Label the "net"and find thesurface area
112 Surface Areas of Prisms and Cylinders 2011
10
March 24, 2011
Solid Net
15 in.
6 in.
6 in.
6 in.
6 in.6 in.
6 in. 6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
15 in.
15 in.
15 in.
15 in.
15 in.
A = 36
A = 36 A = 90
A = 90
A = 90
A = 90
112 Surface Areas of Prisms and Cylinders 2011
11
March 24, 2011
6 in.
6 in.
6 in. 6 in.
6 in. 6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
6 in.
15 in.
15 in.
15 in.
15 in.
15 in.
A = 36
A = 36 A = 90
A = 90
A = 90
A = 90
Surface Area
SA = 36 + 36 + 90 + 90 + 90 + 90 = 72 + 360 = 432 square inches
112 Surface Areas of Prisms and Cylinders 2011
12
March 24, 2011
Find the surface area of this prism.
112 Surface Areas of Prisms and Cylinders 2011
13
March 24, 2011
112: Day 2 Surface areas on prisms and cylinders.
WarmupDraw the nets of each figure below.
112 Surface Areas of Prisms and Cylinders 2011
14
March 24, 2011
Cylinder
112 Surface Areas of Prisms and Cylinders 2011
15
March 24, 2011
.
h
r
112 Surface Areas of Prisms and Cylinders 2011
16
March 24, 2011
h
r
r
h
Circumference of circle (2 r)
Circumference of circle (2 r)
.
h
r
112 Surface Areas of Prisms and Cylinders 2011
17
March 24, 2011
h
r
r
h
Circumference of circle (2 r)
Circumference of circle (2 r)
SA of Cylinder:
2 (Area of Circle) + Area of Rectangle
Therefore, the formula can be simplified to:
2 r (r + h)SA =
112 Surface Areas of Prisms and Cylinders 2011
18
March 24, 2011
Try One!!
h
rh = 12 in.r = 3 in.
(Use = 3.14)
1. Start with the formula
2 r (r + h)SA =
2. Plug in the numbers
112 Surface Areas of Prisms and Cylinders 2011
19
March 24, 2011
WarmUp
Find the Area of each Net.
112 Surface Areas of Prisms and Cylinders 2011
20
March 24, 2011
Example
112 Surface Areas of Prisms and Cylinders 2011
21
March 24, 2011
Classwork
112 Surface Areas of Prisms and Cylinders 2011
22
March 24, 2011
112 Surface Areas of Prisms and Cylinders 2011
23
March 24, 2011
Homeworkp. 611#13, 515
﴾surface area only﴿
Try #3335 for extra credit. You must show all your work.
112 Surface Areas of Prisms and Cylinders 2011
24
March 24, 2011
