# The length of a string attached to a wall?

I feel really dumb for asking this question. I apologize in advance.

When the example of a string attached to a wall is given to explain waves and the ressonance frequencies, the length of the string is given by $$L$$, which is the length of a straight line in the $$x$$ axis from the hand to the wall. How can that be if it is an arc? Shouldn't it be higher?