Surface

1
Surface Area
2
Surface Area

• What does it mean to you?
• Does it have anything to do with what is in the
  inside of the prism.?
• Surface area is found by finding the area of all
  the sides and then adding those answers up.
• How will the answer be labeled?
• Units2 because it is area!

3
Rectangular Prism
How many faces are on here?
6
Find the area of each of the faces.
Do any of the faces have the same area?
A 5 x 4 20 x 2 40
If so, which ones?
B 6 x 5 30 x 2 60
C 4 x 6 24 x 2 48
Opposite faces are the same.
148 in2
Find the SA
4
Cube
Are all the faces the same?
YES
A
How many faces are there?
4m
6
Find the Surface area of one of the faces.
4 x 4 16
Take that times the number of faces.
X 6 96 m2
SA for a cube.
5
Triangular Prism
How many faces are there?
4
5
5
How many of each shape does it take to make this
prism?
10 m
3
2 triangles and 3 rectangles SA of a triangular
prism
Find the surface area. Start by finding the area
of the triangle.
x 2 12
4 x 3/2 6
How many triangles were there?
5 x 10 50 front 4 x 10 40 back 3 x 10
30 bottom
2
Find the area of the 3 rectangles.
SA 132 m2
What is the final SA?
6
SA

• You can find the SA of any prism by using the
  basic formula for SA which is
• 2B LSA SA
• LSA lateral Surface area
• LSA perimeter of the base x height of the prism
• B the base of the prism.

7
Triangular Prisms

• Use the same triangular prism we used before.
  Lets us the formula this time. 2B LSASA
• Find the area of the base, which is a triangle
  because it is a triangular prism. You will need
  two of them.
• Now, find the perimeter of that same base and
  multiply it by how many layer of triangles are in
  the picture. That is the LSA.
• Add that to the two bases. Now you should have
  the same answer as before.
• Either way is the correct way.

8
Cylinders
What does it take to make this?
6
10m
2 circles and 1 rectangle a cylinder
2B LSA SA
2 B
3.14 x 9 28.26
X 2 56.52
LSA(p x H)
3.14 x 6 18.84 x 10 188.4
SA
244.92
9
SURFACE AREA

• Why should you learn about surface area?
• Is it something that you will ever use in
  everyday life?
• If so, who do you know that uses it?
• Have you ever had to use it outside of math?