12-2: Surface Area of Prisms and Cylinders. The LATERAL AREA of a solid figure is the sum of the...
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Transcript of 12-2: Surface Area of Prisms and Cylinders. The LATERAL AREA of a solid figure is the sum of the...
12-2: Surface Area of Prisms and Cylinders
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
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
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:
3 cm8 cm
5 cm
2(8) + 2(3) = 22 cm
(8)(3) = 24 cm
S = 110 + 2(24) = 158 cm2
22(5) = 110 cm2
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
4 in3 in
c in13 in
So what is “c”?32 + 42 = c29 + 16 = c2
25 = c2
5 = cWhat is Pbase?12 in
½ (4)(3) = 6 in
S = (12)(13) + 2(6) = 168 in2
(12)(13) = 156 in2
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 acylinder is▫S = 2πrh + 2πr2
h h
rr
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:
11 ft
8 ft8 / 2 = 4 ft
11 ft
S = 2π(4)(11) + 2π(4)2 376.99 ft2
2(4)(11) 276.46 ft2
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 =
6 cm
5 cm188.5 cm2
345.58 cm2
12-2: Surface Area of Prisms and Cylinders•Assignment
▫Worksheet #12-2