It is not a true biconditional.
Answer:

Step-by-step explanation:
If that is a square, then all sides are the same. Therefore, it's a
by
shape. We'll use Pythagorean Theorem to find the diagonal.

Since it's not a fraction, there is no denominator to rationalize. Let me know if you have any other questions!
The first one I think not sure
Answer:
64%
Step-by-step explanation:
.64 is equal to 64%
In order to convert move the decimal over two spaces and add a percent sign (%).
Move the decimal 0.64 to 64 and add percent sign 64%.