SOLUTION: 1. A semicircular window of radius 12 inches is to be laminated with a sunblock coating that costs $0.75 per square inch to apply. What is the total cost of coating the window, to

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Question 198670: 1. A semicircular window of radius 12 inches is to be laminated with a sunblock coating that costs $0.75 per square inch to apply. What is the total cost of coating the window, to the nearest cent? (Use п = 3.14. Hint: Area of Circle: A = пrē)
Found 2 solutions by jojo14344, nerdybill:
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


*Note: A%5BC%5D=%28pi%29r%5E2

So, "Half" of this is a semi-circle, %281%2F2%29%28pi%29r%5E2

With r = 12 inches,
=%281%2F2%29%28pi%2912%5E2=%281%2F2%29%28pi%29144
=red%2872%28pi%29in%5E2%29

Then, %28Cost%2FArea%29%28Area%29
=%280.75%2Fcross%28in%5E2%29%29%2872%28pi%29cross%28in%5E2%29%29
=54%28pi%29 ---> $169.65, Answer

Thank you,
Jojo

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
A semicircular window of radius 12 inches is to be laminated with a sunblock coating that costs $0.75 per square inch to apply. What is the total cost of coating the window, to the nearest cent? (Use п = 3.14. Hint: Area of Circle: A = пrē)
.
Area of a circle given r = 12:
(pi)r^2
=(3.14)(12^2)
=(3.14)(144)
=452.16 sq inches
.
Since the window is semicircular take 1/2 of above:
(1/2)452.16
=226.08 sq inches
.
Cost = .75(226.08) = $169.56