Answer:
A. 8
Step-by-step explanation:
The angle shown is a 90 degree right angle (shown by the box where the vertex is)
We see that the first angle inside the right angle is 50 degrees, so the other angle must be 40 because the degrees must add up. We can set up an equation here.

After dividing both sides by 5, we get x = 8
Answer:The slopw is -1/2
Step-by-step explanation
A slope that is a opposite reciprocal of another slope is always perpendicular. Make sure it is a opposite reciprocal. Not just a regular reciprocal.
4 because 2 shoes for each stock pair and 4 × 2 = 8
Let
be the dimensions of the rectangle. We know the equations for both area and perimeter:


So, we have the following system:

From the second equation, we can deduce

Plug this in the first equation to get

Refactor as

And solve with the usual quadratic formula to get

Both solutions are feasible, because they're both positive.
If we chose the positive solution, we have

If we choose the negative solution, we have

So, we're just swapping the role of
and
. The two dimensions of the rectangle are
and 
Answer:
?
Step-by-step explanation: