"Acute" means "between 0 and 90 degrees," and "obtuse" "between 90 and 180 degrees. Given an acute angle, we find the supplement by subtracting the acute angle from 180 degrees; the result is obtuse.
The question is asking for a fourth of a third. 1/4 of 1/3 "of" = multiplying in math 1/4 x 1/3 = 1/12 That means it is cut in twelfths and it has 12 slices.
