Area formula for a circle is pi *r^2
circumference is pi * d
22.6/3.14 is 7.197= diameter
radius= 3.5985
pi * (3.5985)^2 =40.66
area is about 40.66 square inches
If you’re talking about supply and demand, demand is how much people want of something, and the suppliers how much of it is available. If there is more demand then there is supply, the price of the product will go up. If there is more supplied and there is demand, the price will go down.
The reason why one case of influenza does not confer lifelong immunity is that the virus tends to mutate overtime which makes it unrecognizable to the immune system.
<h3>Why is it difficult to get immunity to influenza?</h3>
Influenza is caused by a virus which tends to mutate overtime in order to stay ahead of medical technology.
As a result, this mutation makes the original virus unrecognizable to the immune system which would then be unable to fight it.
Find out more on natural immunity at brainly.com/question/21480961
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