Hello let me walk you though this! :)
So iambic pentameter is unstressed syllables followed by stressed syllables in a total of 5 measures.
Trochaic tetrameter is stressed syllable followed by an unstressed syllable in a total of 4 measures.
Anapestic tetrameter is two unstressed syllables followed by a stressed syllable in total of 4 measures.
Dactylic pentameter is a stressed syllable followed by two unstressed syllables in a total of 5 measures.
We can look at these as the following
Iambic: ˘ ¯
Trochaic: ¯ ˘
Anapestic: ˘ ˘ ¯
Dactylic: ¯ ˘ ˘
If you notice the pattern an easy way to remember them is that they are opposites of each other. So now lets look a the text given.
" The Assyrian came down like the wolf on the fold."
Looking at this we can recognize the meter as two unstressed syllables followed by a stressed syllable in total of 4 measures.
Making our answer be Anapestic tetrameter.
Hope I helped! If you have any other questions or would further explanation just let me know! :)