Question

surface area - cone
find the surface area of each cone. round your answer to two decimal places.
(use $pi = 3.14$)
1)
surface area =
2)
surface area =
3)
surface area =
4)
surface area =
5)
surface area =
6)
surface area =
7)
8)
surface area =
9)
surface area =

Explanation:

The total surface area of a cone is given by the formula:
$$SA = \pi r(r + l)$$
where $r$ is the radius of the base, and $l$ is the slant height. We use $\pi=3.14$ for all calculations, and round to 2 decimal places.

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1) Cone 1 (r=2 in, l=7 in)

Step1: Plug values into formula

$SA = 3.14 \times 2 \times (2 + 7)$

Step2: Compute step-by-step

$SA = 3.14 \times 2 \times 9 = 3.14 \times 18 = 56.52$

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2) Cone 2 (r=9 ft, l=11 ft)

Step1: Plug values into formula

$SA = 3.14 \times 9 \times (9 + 11)$

Step2: Compute step-by-step

$SA = 3.14 \times 9 \times 20 = 3.14 \times 180 = 565.20$

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3) Cone 3 (r=5 yd, l=10 yd)

Step1: Plug values into formula

$SA = 3.14 \times 5 \times (5 + 10)$

Step2: Compute step-by-step

$SA = 3.14 \times 5 \times 15 = 3.14 \times 75 = 235.50$

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4) Cone 4 (r=11 ft, l=15 ft)

Step1: Plug values into formula

$SA = 3.14 \times 11 \times (11 + 15)$

Step2: Compute step-by-step

$SA = 3.14 \times 11 \times 26 = 3.14 \times 286 = 898.04$

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5) Cone 5 (r=10 yd, l=20 yd)

Step1: Plug values into formula

$SA = 3.14 \times 10 \times (10 + 20)$

Step2: Compute step-by-step

$SA = 3.14 \times 10 \times 30 = 3.14 \times 300 = 942.00$

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6) Cone 6 (r=3 in, l=4 in)

Step1: Plug values into formula

$SA = 3.14 \times 3 \times (3 + 4)$

Step2: Compute step-by-step

$SA = 3.14 \times 3 \times 7 = 3.14 \times 21 = 65.94$

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7) Cone 7 (r=13 yd, l=19 yd)

Step1: Plug values into formula

$SA = 3.14 \times 13 \times (13 + 19)$

Step2: Compute step-by-step

$SA = 3.14 \times 13 \times 32 = 3.14 \times 416 = 1306.24$

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8) Cone 8 (r=8 in, l=14 in)

Step1: Plug values into formula

$SA = 3.14 \times 8 \times (8 + 14)$

Step2: Compute step-by-step

$SA = 3.14 \times 8 \times 22 = 3.14 \times 176 = 552.64$

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9) Cone 9 (r=6 ft, l=12 ft)

Step1: Plug values into formula

$SA = 3.14 \times 6 \times (6 + 12)$

Step2: Compute step-by-step

$SA = 3.14 \times 6 \times 18 = 3.14 \times 108 = 339.12$

Answer:

1. $56.52$ square inches
2. $565.20$ square feet
3. $235.50$ square yards
4. $898.04$ square feet
5. $942.00$ square yards
6. $65.94$ square inches
7. $1306.24$ square yards
8. $552.64$ square inches
9. $339.12$ square feet