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Bisecting Bakery sells cylindrical round cakes. The most popular cake at the bakery is the red velvet cake. It has a radius of 15 centimeters and a height of 12 centimeters.

If everything but the circular bottom of the cake was iced, how many square centimeters of icing is needed for one cake? Use 3.14 for π and round to the nearest square centimeter.

810 cm2
585 cm2
2,543 cm2
1,837 cm2

User Geekgirl
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1 Answer

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The surface area of the icing on the cake can be found by calculating the lateral surface area of the cylinder. The formula for the lateral surface area of a cylinder is:

Lateral Surface Area = 2πrh

where r is the radius of the cylinder and h is the height of the cylinder.

In this problem, the radius of the cake is 15 cm and the height of the cake is 12 cm. Therefore, the lateral surface area of the cake is:

Lateral Surface Area = 2π(15 cm)(12 cm)
Lateral Surface Area = 2π(180 cm²)
Lateral Surface Area = 360π cm²
Lateral Surface Area ≈ 1131 cm²

So, the amount of icing needed for one cake is approximately 1,131 square centimeters. However, we need to subtract the area of the circular bottom of the cake from this value. The area of the circular bottom of the cake is:

Area of circular bottom = πr²
Area of circular bottom = π(15 cm)²
Area of circular bottom = 225π cm²
Area of circular bottom ≈ 706.5 cm²

Therefore, the amount of icing needed for one cake is approximately:

1131 cm² - 706.5 cm² ≈ 424.5 cm²

Rounding this value to the nearest square centimeter, we get:

425 cm²

So, the answer is not listed. The amount of icing needed for one cake is approximately 425 square centimeters.
User Zajke
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