#1
That is false..one could have side lengths of 9 and 1, and the other could have side lengths of 3. Both the areas would be 9, but the figures would not be congruent.
#2
That is true, they must both have the same side length to have the same perimeter, therefore they will also have the same area.
The answer is
The side length of the square Kevin cuts is slightly less than the length the instructor required
The speed of the current is 40.34 mph approximately.
<u>SOLUTION:
</u>
Given, a man can drive a motorboat 70 miles down the Colorado River in the same amount of time that he can drive 40 miles upstream.
We have to find the speed of the current if the speed of the boat is 11 mph in still water. Now, let the speed of river be a mph. Then, speed of boat in upstream will be a-11 mph and speed in downstream will be a+11 mph.
And, we know that, 

We are given that, time taken for both are same. So 
