Two angles of a quadrilateral are said to be opposite angles if they are not adjacent angles.
In the figure, ABCD is a quadrilateral. (i) Name a pair of adjacent sides. (ii) Name a pair of opposite sides. (iii) How many pairs of adjacent sides are there? (iv) How many pairs of opposite sides are there?
(v)Name a pair of adjacent angles. (vi) Name a pair of opposite angles. (vii) How many pairs of adjacent angles are there? (viii) How many pairs of opposite angles are there?
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 _______.