Transcript Surface Area of nets

Warm Up
Find the perimeter and area of each polygon. Show
work and include units!
20 m
1.
2.
6 in
12 m
5 in
25 m
7 in
3.
13 m
14 cm
8 cm
11 cm
12 m
Lesson 5-1:
Surface Area of Cubes and
Rectangular Prisms
I can…
• find the surface area of a
cube.
• find the surface area of a
rectangular prism.
Vocabulary
•Surface Area
•Net
•Cube
•Right Prism
Surface Area
 The total area of the surface of a three
dimensional object
*We will use nets to help us
determine the surface area
Net
 A two-dimensional figure that can be folded
on its segments or curved on its boundaries to
form a three-dimensional figure.
Cube
 A three-dimensional figure with 6 square
faces.
Surface Area of a Cube

First, let’s draw a net of a cube.
1. If one side length is 3 cm
long, what is the area of one
square?
9 squared cm
2. How many squares do
we have?
6 squares
3. What is our surface
area for this cube?
54 squared cm
Video Over Surface Area of a Cube

http://www.youtube.com/watch?v=sskf3tF2heU
Examples

What is the surface area of the cube?
Right Prism
 A prism that has
two bases, one
directly above the
other, and has its
lateral faces as
rectangles.
Rectangular Prism
 A prism with six rectangular faces.
Video Over Surface Area of a Rectangular
Prism

http://www.youtube.com/watch?v=oR1ukNC1pvA
Surface Area of a Rectangular Prism

First, let’s draw a net of a rectangular prism.
SA= 2[(length x width) +(length x height)+(width x height)]
SA= 2[(3 x 2)+(3 x 6)+(2 x 6)]
SA= 2[(6)+(18)+(12)]
SA= 2(36)
SA= 72 squared cm
Examples

What is the surface area of the rectangular prism?
SA= 2[(5 x 4)+(5 x 10)+(4 x 10)]
SA= 2[(20)+(50)+(40)]
SA= 2(110)
SA= 220 squared cm