To evaluate the expression \(\sqrt{64 + 36}\), we first calculate the sum inside the square root:
\[ 64 + 36 = 100 \]
Now we can find the square root:
\[ \sqrt{100} = 10 \]
So, the root is a real number.
The correct choice is:
A. The root is a real number and \(64 + 36 = 100\).