Well
we know that the formula for a diagonal is:

so using this we can conclude that the length and the width of this particular square would be 7.071 cm. Hope this helps!
Answer: In order to find what the coordinates of B are is by trying to know how we got to (-2,0) of line AB. You have to subtract 3 from A coordinate x which is 1,it will give you -2, and you have to subtract 1 from A coordinate y which is 1,it will give you 0.
All circles are similar.
If they were congruent, they would have the same radius's/diameter's.
Circle B = diameter of 6
Circle A = radius of 4
Diameter = 2 * Radius
Circle A = diameter of 4 * 2 = 8
So they have different diameter's, therefore they are not congruent. So they are similar only.
2 is the answer I believe
It is rounded to 10,000
Hopes that Helps :]