meg is an engineer who designs watch batteries. the battery shes currently designing is shaped like a…

meg is an engineer who designs watch batteries. the battery shes currently designing is shaped like a cylinder with a base diameter of 6.8 millimeters and a height of 2.1 millimeters. what is the surface area of the battery? use $piapprox3.14$ and round your answer to the nearest whole number. square millimeters
Answer
Explanation:
Step1: Find the radius
The diameter $d = 6.8$ mm, so the radius $r=\frac{d}{2}=\frac{6.8}{2}=3.4$ mm.
Step2: Calculate the area of the two - bases
The area of a circle is $A_{base}=\pi r^{2}$. The area of two bases $A_{2bases}=2\pi r^{2}$. Substitute $r = 3.4$ mm and $\pi\approx3.14$: $A_{2bases}=2\times3.14\times3.4^{2}=2\times3.14\times11.56 = 72.5344$ $mm^{2}$.
Step3: Calculate the lateral surface area
The lateral - surface area of a cylinder is $A_{lateral}=2\pi rh$. Substitute $r = 3.4$ mm, $h = 2.1$ mm and $\pi\approx3.14$: $A_{lateral}=2\times3.14\times3.4\times2.1=44.8744$ $mm^{2}$.
Step4: Calculate the total surface area
The total surface area of a cylinder $A = A_{2bases}+A_{lateral}$. So $A=72.5344 + 44.8744=117.4088\approx117$ $mm^{2}$.
Answer:
117