1 and 6 are not corresponding angles. They have different degrees. hope this helps :)
        
                    
             
        
        
        
You first need to make the denominators on both fractions the same and how to do that is simple. What does 6 and 8 go into to? Well, the answer is 24. You multiply 5/6 into 4 and you should get 20/24. Then, you multiply 3/8 into 3 and you should get 9/24. Now the last part is easy, you just subtract 20/24 and 9/24 and you should get 11/24 as your answer. It cannot be simplified. Hope it helped.
        
                    
             
        
        
        
We have that
If you draw a diagram, and draw perpendiculars from the intersection to the sides of the rectangle, you will see they are the mid point of each side. 
see the attached figure
<span>If the mid point of the smaller side is ---------> x. 
The mid point of the larger side will be -----------> (x + 4) </span>
The full length if the smaller side will be 2x and the length of the larger side will be 2(x + 4) = 2x + 8 
The perimeter = 2 times the length + 2 times the width. 
2(2x + 8) + 4x = 56 
4x + 16 + 4x = 56 
8x = 40 
x = 5 
Therefore 
length = 2x + 8 = 18cm 
<span>width = 2x = 10cm
</span>
the answer is
<span>the lengths of the sides of the rectangle are
</span>
length = 18cm width = 10cm