Answer: 
Step-by-step explanation:
The measure of the third unknown arc is
.
So, 
Finding three volume is super easy the equation for volume is the area of the base times the height so u will find the area of all the small part and then add those and then multiply by the height
The equivalent expression of
is 
<h3>How to determine the equivalent expression?</h3>
The logarithmic expression is given as:

The law of logarithm states that:
log(a) - log(b) = log(a/b)
This means that the expression can be split as:

Hence, the equivalent expression of
is 
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