Answer:
Step-by-step explanation:
It the wiper blade (and arm) made a full rotation, 2 circles would be formed.
One small circle with radius
b, and a larger circle with radius
a+b.
The areas of these 2 circles are respectively:

and

120° is 1/3 of a complete angle 360° which form a circle, so the areas formed by the arm of length b, and the arm + the wiper blade (a+b) are:

and

in squared respectively.
the actual wiped area is

(in squared)
Area of the window is 54*24= 1296 (in squared)
thus, the ratio of the wiped area to the whole area of the window is 351.7/1296=0.271
Converted to percentages, this is 27.1%
Answer: 27.1%
You mean, what is this number?
we can rephrase it like this: the sum of a number x and 8 is 15
which is:
x+8=15
we subtract 8 from both sides and we get
x=7
so the answer is 7.
You would then ask the customers for their opinion on the heat and how much drinks they order
The answer is 77. if you do it the opposite way and multiply