Question

what is the surface area of this cone? round your answer to the nearest hundredth. 6 mm 4.2 mm square millimeters

Explanation:

Step1: Find the radius

The diameter $d = 4.2$ mm, so the radius $r=\frac{d}{2}=\frac{4.2}{2}=2.1$ mm.

Step2: Recall the surface - area formula for a cone

The surface area of a cone $A=\pi r(r + l)$, where $r$ is the radius and $l$ is the slant height. Here, $l = 6$ mm and $r = 2.1$ mm.

Step3: Calculate the surface area

$A=\pi\times2.1\times(2.1 + 6)$
$A=\pi\times2.1\times8.1$
$A = 17.01\pi$
$A\approx17.01\times3.14159$
$A\approx53.44$ square millimeters

Answer:

$53.44$