Fill in the blanks: (i) If two angles are complementary, then the sum of their measures is .
(ii) If two angles are supplementary, then the sum of their measures is .
(iii) Two angles forming a linear pair are .
(iv) If two adjacent angles are supplementary, they form a .
(v) If two lines intersect at a point, then the vertically opposite angles are always
.
(vi) If two lines intersect at a point, and if one pair of vertically opposite angles are
acute angles, then the other pair of vertically opposite angles are .