Ex:
alt (altitude) = 12
base = 5

output:
xxxxx
xxxx
xxxx
xxxx
xxx
xxx
xxx
xx
xx
xx
x
x

The first column and the first row are defined and set by alt and base, respectively.
That leaves the matter of the ‘inner triangle.’
Inner triangle:
    w – the width of the inner triangle is base-2
   | |
 --xxx --
 | xxx   | n - the height of each box is l/w
 | xxx --
 | xx
L| xx
 | xx
 | x
 | x
 | x
 --[space] – box0 – the number of spaces at the end is l%w

The length of the inner triangle (L) is alt-2

In this case, alt is larger, so n = l/w
box0 = l%w

the width of each box is w (reassigned to nn) – 1 for each box until nn = 0

the function drawline takes the first value and prints it the second value’s times. The third value is a Boolean value for whether or not a new line is printed at the end.