1. Let's clarify the problem: You asked if $x.y$ gives the length of $x+y$. 2. Typically, $x.y$ denotes the product of $x$ and $y$, while $x+y$ denotes their sum. 3. The "length" of a number is not a standard term in algebra, but if you mean the absolute value or magnitude, then the length of $x+y$ is $|x+y|$. 4. The product $x.y$ is not generally equal to the length (absolute value) of $x+y$. 5. For example, if $x=2$ and $y=3$, then $x.y=6$ but $|x+y|=|5|=5$, which are not equal. 6. Therefore, $x.y$ does not give the length of $x+y$ in general. 7. If you meant something else by "length," please clarify!