What it takes to make a scalable Christmas tree in Ruby?

christmass_tree.rb

#Simple tree that will look as an arrow :D
height = 20
((1..height).to_a+[6]*height.div(5)).map do |i|
  puts ('*'*i*2).center(80)
end


#Simple tree that look more like a doodle christmas tree
height = 20
(
  (1..height.div(2)).to_a +
  (height.div(4)..(height.div(2)+height.div(4))).to_a +
  (height.div(2)..height).to_a +
  [3]*height.div(3)
).map do |i|
  puts ('*'*i*4).center(80)
end

#Or almost one liner
height = 20
((1..height.div(2)).to_a+(height.div(4)..(height.div(2)+height.div(4))).to_a+(height.div(2)..height).to_a+[3]*height.div(3)).map do |i|
  puts ('*'*i*4).center(80)
end