For the first question you need to find the formula for the rectangle, after you did that fill it in. and find your answer.
Answer:

Step-by-step explanation:
Since we're looking at perpendicular lines, the slope of the new line is the reciprocal of the original line.
So the slope of our new line is 
So far, we are looking at 
Now we need to find the b value by plugging in the given point.

So the final equation is 
Rounded to 1 decimal place
Is this simultaneous equations?
if yes then the first step is
make one of the unknown as the subject
If the circumference is half of the perimeter than the area for both circles would be half of them find one circles area and half it