Hello !
cos (a+b) = cos a cos b - sin a sin b
sin (a+b) = sin a cos b + sin b cos a
cos (a+b+c) = cos (a+(b+c))
cos (a+b+c) = cos a cos (b+c) - sin a sin (b+c)
cos (a+b+c) = cos a (cos b cos c - sin b sin c) - sin a (sin b cos c + sin c cos b)
cos (a+b+c)=cos a cos b cos c - cos a sin b sin c - sin a sin b cos c - sin a cos b sin c
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
True, bc they add up to 180 and are the same size.
I believe the answer is
.5
