Where would you go to set up margins on a letter

What does vexed mean as it is used in the second stanza of "the second coming"?

Read the excerpt from "the blackfeet creation." how do readers know that this excerpt is from a myth? the excerpt describes an animal called a muskrat. the excerpt describes old man drying the mud. the excerpt describes old man scattering mud over water. the excerpt describes how muskrat create land.

What is central purpose of the letter