3. Surface Areas of Pyramids and Cones
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The lateral area of a right cone is half the product of the circumference of the base and the slant height.
1044in^2
We want to find the lateral area of the given cone.
In this formula, r is the radius and l is the slant height of the cone. Although we do not have the slant height, we can find it using the Pythagorean Theorem. Since the diameter of the base is 26 inches, we have that its radius is 26÷ 2=13 inches.
Substitute values
Calculate power
Add terms
sqrt(LHS)=sqrt(RHS)
Rearrange equation
r= 13, l= sqrt(653)
Use a calculator
Round to nearest integer