I don't understand the Challenge 5: Draw a Triangle app!?

I don’t understand the Challenge 5: Draw a Triangle app!? At: https://docs.google.com/document/d/1DI-4RkYkRl8EPY17TOwfK8gCl--KMdqLEPP-hz6QHI0/edit# can someone please explain what I’m supposed to do, please :]

its just a practice exercise to draw a right angle triangle in terms of height

so an input of 4 (height) will get the output

1 *
2 **
3 ***
4 ****