It is the Fresko technique
Answer:
Fresko technique
Yeah!!
Explanation:
c
abcd
so because the string quartet is by Haydn and they it is in themes a and b therefore that it the insert
I have never actually seen a zigzag ruler, but I would assume to make zigzag lines.
F, G, A, Bb, C, D, E, F
WWHWWWH (see picture)