By the binomial theorem,
where
Then the coefficients of the 
terms in the expansion are, in order from 
to 
,
H = 6 in
V=bh
H=v/b
H=36/6
H=6
<h3>
Answer: 9</h3>
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Work Shown:
a = unknown = leg #1
b = 12 = leg #2
c = 15 = hypotenuse
Plug those values into the pythagorean theorem and solve for 'a'
a^2 + b^2 = c^2
a^2 + (12)^2 = (15)^2 .... substitution
a^2 + 144 = 225
a^2 = 225 - 144 ... subtracting 144 from both sides
a^2 = 81
a = sqrt(81) .... applying square root to both sides
a = 9
6.875 average.
To calculate the average you add up all of the numbers and divide it by the number of numbers there are, in this case there are 4 numbers. So you add 3.25+6.5+7.25+10.5 and divide that by 4
