Explanation:
what happens, if I cut something in half ?
not just into 2 pieces, but outright in half ?
a pizza or a cake ?
well, I get 2 identical pieces.
a bisector (bi = 2 or double, sector = part) splits an angle into 2 equal parts.
that means
33 = 4x + 1
from there we get
32 = 4x
x = 32/4 = 8