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Lesson 11-4 Pages 573-577. Surface Area: Prisms and Cylinders. What you will learn!. How to find surface area of prisms. How to find surface area of cylinders. Vocabulary. What you really need to know!.
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Lesson 11-4Pages 573-577 Surface Area: Prisms and Cylinders
What you will learn! • How to find surface area of prisms. • How to find surface area of cylinders.
What you really need to know! To find the surface area S of a rectangular prism with length l, width w, and height h, use the formula: S = 2lw + 2lh + 2wh.
What you really need to know! To find the surface area S of a triangular prism, find the area of each face, then add to find the total surface area.
What you really need to know! To find the surface area S of a cylinderwith radius r and height h, use the formula: S = 2r2 + 2rh
Example 1: Find the surface area of the rectangular prism:
S = 2lw + 2lh + 2 wh S = 2•34•21 + 2•34•4 + 2•21•4
S = 1,428 + 272 + 168 S = 1,868 cm2
Example 2: Find the surface area of the triangular prism. A triangular prism is made up of 2 triangles and 3 rectangles.
Example 2: Find the surface area of the triangular prism. 2(½ x 12 x 16) + (20 x 3) + (16 x 3) + (12 x 3) 192 + 60 + 48 + 36 336 m2
Example 3: Find the surface area of the cylinder. Round to the nearest tenth. S = 2r2 + 2rh S = 2•2.52 + 2•2.5•8 S = 164.9 m2
Example 4: A company packages its cereal in a rectangular prism that is 2.5 in. by 7 in. by 12 in. It is considering packaging it in a cylinder-shaped container having a 6-in. diameter and a height of 7.5 in. Which uses the least amount of packaging?
S = 2lw + 2lh + 2 wh S = 2(12•2.5) + 2(12•7) + 2(2.5•7) S = 263 in2 S = 2r2 + 2rh S = 2•32 + 2•3•7.5 S ≈ 197.9 in2
Page 576 Guided Practice #’s 3-8
Read: Pages 573-575 with someone at home and study examples!
Homework: Pages 576-577 #’s 9-18, 25, 26, 30, 31
Prepare for Mid-Test! Pages 595-597 #’s 9-20 Odd Answers in Back of Book!
Page 751 Lesson 11-4
Page 576 # 11 10 m 9 m 6 m 8 m 8 m
Page 576 # 11 10 m 9 m 6 m 8 m 8 m