Aim: How do we find the surface area of three dimensional figures?

1
Aim How do we find the surface area of three
dimensional figures?
Do Now
Find area of shaded region.
2

• all edges are same measure

12
Cube

• all faces are squares

6
A, B, D
3
For each of these unfolded cubes, determine the
color that will be opposite the red face when
folded.
Blue
(B)
(A)
Green
(C)
(D)
Purple
Brown
4
Find the surface area of cube with edge 10
600 sq. units
The surface area is the sum of the areas of the
faces of the polyhedron.
5
Rectangular Prism
Faces? Shapes?
6
4 rectangles 2 squares
The surface area is the sum of the areas of the
faces of the polyhedron.
1000 sq. units
6
Right Pyramid with square base
Faces? Shapes?
5
1 square base



4 triangles

100
A of Square s2
The surface area is the sum of the areas of the
faces of the polyhedron.
A of Triangle 1/2 bh
A of each triangle 1/2 (10)(15) 75
400 sq. units
7
Cylinder
Faces? Shapes?
3
2 circles
1 rectangle
A of Circle ?r2
C ? D D 2r
3.14 D length of rectangle and the circumference
of the circle
A of rectangle lw
S.A. of cylinder 2?r2 2?rh
Find the surface area if r 5 and h 10
8
Find the surface area of a cylinder if r 5 and
h 10
A of Circle ?r2
C ? D D 2r
A of rectangle lw
(10)(3.14)(10) 314
S.A. of cylinder 2?r2 2?rh
A of each circle 3.14(5)2 78.5 ? 157 sq.
units (2)
A of rectangle (10)(3.14)(10) 314 sq.
units
Surface area of cylinder 471 sq units
9
A cylindrical cement pipe has length 500 ft and
diameter 3 ft. If you are to paint the exterior
of the pipe, how many square feet will you paint?
Leave your answer in terms of ?.
C ?D ? width of unfolded pipe
w ?3
Exterior area of pipe lw (3?)500 1500 ?