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All you have to do to acquire the equation is to substitute the variables to the formula for A and simplify. Since A = 1/2*b*h and h = bsin(C), then A can be in terms of one variable only, which is b.
A = 1/2*b*bsin(c)
A = 1/2*b^2*sin(C)
Answer:
first one
Step-by-step explanation:
Let
x---------> the thickness of the frame in feet
At-------> Area of the mirror and the frame in square feet
we know that
------> equation 
--------> equation 
equate equation
and equation 

therefore
the answer is the option

Answer:
he gets 4.33 dollars back
Step-by-step explanation:
add 2.75+1.20+1.35+0.37= 5.67
10-5.67=4.33 $