This is true.
These are perfect squares: 4, 9, 25. These are not: 7, 8, 11
Yes because all sides would be equal to 5 which would give you 5*4 = 20 units.
ANSWER
The product is

EXPLANATION
To find the product of

and

means we should multiply the two fractions.
We multiply to obtain,


Cancel the common factors:

Now, multiply the numerators separately and the denominators too separately.

This simplifies to,

Step-by-step explanation:
(b) If
then
Note that
cancel out so we get

Solving for
we get

(c) I'm not sure what the problem is asking for but here goes. As r doubles,
becomes

CQE is a right angle. Hope this helps!!!