Question

what is the surface area of this cone? round your answer to the nearest hundredth. 15 mm 20 mm square millimeters

Explanation:

Step1: Find the radius

The diameter is 20 mm, so the radius $r=\frac{20}{2}=10$ mm.

Step2: Recall the surface - area formula

The surface - area formula of a cone is $A = \pi r(r + l)$, where $l$ is the slant height. Here, $l = 15$ mm and $r = 10$ mm.

Step3: Calculate the surface area

$A=\pi\times10\times(10 + 15)=\pi\times10\times25=250\pi\approx 250\times3.14159 = 785.3975$ square millimeters.

Step4: Round the answer

Rounding 785.3975 to the nearest hundredth gives 785.40 square millimeters.

Answer:

785.40