Answer:
:)
Step-by-step explanation:
For simplicity I will substitue  for β.
 for β.

In the first step I used the identity
 
 
And I factored out 
Then it's just simple algebra to cancel till the 3rd step where we used another identity derived from the Pythagorean Theorem.

That's it!
 
        
             
        
        
        
I reduced the equation to a - 6 (2/3)
        
             
        
        
        
For a rectangle, A = LW.
A = (3x + 2)(x - 4)
A = 3x^2 - 12x + 2x - 8
A = 3x^2 -10x - 8
        
             
        
        
        
Answer:
1000
Step-by-step explanation: