Question

if the diameter of a nickel is 0.835in and the width of each nickel is 0.077in what is the approximate surface area of the roll of nickels? round to the nearest hundredth

Answer 1

we know that

[surface area]=2*[area of the base]+[perimeter of the base]*height
diameter of a nickel = 0.835 in
r=0.835/2----> 0.4175 in
area of the base=pi*r²------> pi*(0.4175)²----> 0.5473 in²
perimeter of the base=2*pi*r----> 2*pi*0.4175-----> 2.6219 in

[surface area]=2*[0.5473]+[2.6219]*0.077----> 1.2965 in²

the answer is
1.30 in²