Transcript Surface Area

Surface area
0506.4.4 Solve problems involving surface area and volume of
rectangular prisms and polyhedral solids.
Perimeter
 Measure each side
 Add all the sides together
13 cm
P = 36 cm
5 cm
Area
 Area of rectangles, triangles, and
parallelograms.
 Rectangles: A = l x w
 Parallelograms: A = b x h
 Triangles: A = ½ b x h
Find the area A = l x w
A = 13 x 5
A = 65 sq cm
13 cm
5 cm
Find the area
5 in
6 in
9 in
A = 45 square in
Remember the rectangle?
A triangle is 1/2
5 in
3 in
3 in
5 in
Find the area
A=½bxh
6 in
A = ½ x 7 in x 6 in
7 in
A = 21 square in
Surface area
 Think back to all our 3D shapes
(polyhedra)
 Name a few
faces
 When finding the surface area of a
figure, you must measure all faces.
 You must know the length and width
of each face.
 Once you have found those lengths,
you must then find the area.
 Let’s take a look.
Lets use a cube.
A net of a cube
Surface Area
 If you add together all of the areas
from the faces of a 3-D shape, then
the total is the surface area. It is the
total amount of space needed to cover
the outer surface of the shape. This is
a property of 3-D shapes, and you
might have noticed it when you've
tried to figure out how much
wrapping paper to use to wrap a
present.
Back to the cube
We must measure
each side before we
can find the surface
area.
Lets say each side
measures 5 cm.
So the area of one
face is???
25 sq cm
What else to do
we need to know?
How many faces are
there?
6 faces total, so…
6 x 25 = 150 sq cm
Formula
Surface Area
Of Rectangles
 (base x height + height x width + width x base) x 2
(b x h + h x w + w x b) x 2
Textbook page
Do # 1-5 as group or on own.
HW- Wb page 205
Crayon, color pencil boxes, or
kleenex box.
 You will measure the length and
Add them
width of each face. (use sq cm)
 Label it with a sharpie.
 Find the area of each face and write
the area in the center.
 Write the sums of each down to find
the surface area of the box.
 Write this total on a sticky note.
 Compare total with a partner.
3 congruent faces…
 Did anyone notice that there are 3
congruent faces?
Workbook page 205
 Work with a partner
Surface area
0506.4.4 Solve problems involving surface area and volume of
rectangular prisms and polyhedral solids.
Video
 http://www.pearsonsuccessnet.com/s
npapp/learn/navigateIDP.do?method
=vlo&internalId=130511100000126
Use the shape from last week.
 Measure each side and find the
surface area. (like the boxes
yesterday)
 Get with other students in the room
with your shape.
 Present to the class as a group how
you found the surface area and what
it is.
Classwork/Homework
 WB page 206
 Possibly assign project
Surface area
0506.4.4 Solve problems involving surface area and volume of
rectangular prisms and polyhedral solids.
Video online
 http://www.youtube.com/watch?v=rg
936mmOE1k&feature=related
 Walk through the steps
Will need to stop and discuss
 Smiley guy -
http://www.youtube.com/watch?v=kn
lc6O6d8BU&NR=1&feature=endscr
een
Boy http://www.youtube.com/watch?v=d
MUT-NY3gzM&feature=related
Turn to page 328 in book
 # 6-10 with a partner
 HW – study guide
 http://www.ixl.com/math/grade-
5/surface-area
 Questions for review if you have
time.