def make_triangle(n, ch):
    """precondition  n > 0 is a integer
ch is a one-character string
postcondition:  returns a string that will print a triangle
of copies of ch with one copy in the first row, two in the second, etc
    """
    if n == 0:
        return ""
    new_row = ch*n + "\n"
    return make_triangle(n - 1, ch) + new_row
def puzzler(n, ch):
    """precondition  n > 0 is a integer
ch is a one-character string
postcondition:  returns a string that will print a triangle
of copies of ch with one copy in the first row, two in the second, etc
    """
    if n == 0:
        return ""
    new_row = ch*n + "\n"
    return new_row + puzzler(n - 1, ch)
print(make_triangle(2, "$"))
print(puzzler(20, "$"))