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How do you find the lateral surface area of a cone ?

User Kaefer
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2 Answers

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Final answer:

To calculate the lateral surface area of a cone, use the formula L = πrl, with π roughly equal to 3.14, where r is the radius and l is the slant height. Measure the radius of the base and calculate or measure the slant height to use in this formula.

Step-by-step explanation:

To find the lateral surface area of a cone, you need the slant height (l) and the radius (r) of the cone. The formula for the lateral surface area (L) is given by L = πrl, where π is approximately 3.14. This formula comes by envisioning unrolling the cone's lateral surface and recognizing that it approximates a sector of a circle whose arc length is the circumference of the base of the cone and radius is the slant height of the cone.

Here is a step-by-step method to calculate it:

  1. Measure the radius (r) of the cone's base.
  2. Calculate the cone's slant height (l) using the Pythagorean theorem if needed.
  3. Use the formula L = πrl to calculate the lateral surface area.
User Orandov
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Surface Area = (3.14)rl+(3.14)r2

l = slant height
User Zpangwin
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