1. 12-2: Surface Area of Prisms and Cylinders

2. 12-2: Surface Area of Prisms and Cylinders
The lateral area of a solid figure is the sum of the area of all its lateral faces (the sides of a figure)
The lateral area of a prism is
L = Ph, where
P = perimeter of the base
h = height h

3. 12-2: Surface Area of Prisms and Cylinders
The surface area of a solid figure is the sum of the area of all its surfaces (the outside of a figure)
The surface area of a prism is
S = Ph + 2B, where
P = perimeter of the base
h = height
B = area of the base h

4. 12-2: Surface Area of Prisms and Cylinders
Find the lateral and surface area of the figure below
L = Ph S = Ph + 2B
What is Pbase?
Lateral Area =
What is Abase?
Plug into the formula for surface area:
2(8) + 2(3) = 22 cm
22(5) = 110 cm2
(8)(3) = 24 cm
S = (24) = 158 cm2
5 cm
3 cm
8 cm

5. 12-2: Surface Area of Prisms and Cylinders
Find the surface area of the figure below
L = Ph S = Ph + 2B
What is Pbase?
Lateral Area =
What is Abase?
Plug into the formula for surface area:
We need to find “c” first
So what is “c”?
= c2
= c2
25 = c2
5 = c
What is Pbase?
12 in
13 in
c in
(12)(13) = 156 in2
3 in
½ (4)(3) = 6 in
4 in
S = (12)(13) + 2(6) = 168 in2

6. 12-2: Surface Area of Prisms and Cylinders
The lateral area of a cylinder
L = 2πrh, where
r = radius
h = height
The surface area of a cylinder is
S = 2πrh + 2πr2 r r h h

7. 12-2: Surface Area of Prisms and Cylinders
Find the lateral area and surface area of the cylinder below
L = 2πrh S = 2πrh + 2πr2
What is r?
What is h?
Lateral Area =
Plug into the formula for surface area:
8 / 2 = 4 ft
8 ft
11 ft
2(4)(11)  ft2
11 ft
S = 2π(4)(11) + 2π(4)2  ft2

8. 12-2: Surface Area of Prisms and Cylinders
Find the lateral area and surface area of the cylinder below
L = 2πrh S = 2πrh + 2πr2 What is r?
Lateral Area =
Surface Area =
188.5 cm2
5 cm
cm2
6 cm

9. 12-2: Surface Area of Prisms and Cylinders
Assignment
Worksheet #12-2