Why isn't this ASCII art printing on multiple lines despite being a multiline string?

I have created a constant which contains some ASCII art of a triangle, like this:

ascii_triangle ='''       /\
     /  \
    /    \
   /      \
  /        \
 /__________\ '''

I then use this as the argument for a function, so I can use the picture within a function (along with some other ASCII art and other arguments). The function isn't important, but the problem is that when I try to print it using

print(ascii_triangle)

within the function, the output looks like this:

       /         /          /           /            /             /__________\ 

How can I make it look like a proper triangle?