In Fig. 16.19, 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?.png)
(i) $(\mathrm{AB}, \mathrm{BC})$ or $(\mathrm{BC}, \mathrm{CD})$ or $(\mathrm{CD}, \mathrm{DA})$ or $(\mathrm{AD}, \mathrm{AB})$
(ii) $(\mathrm{AB}, \mathrm{CD})$ or $(\mathrm{BC}, \mathrm{DA})$
(iii) Four
(iv) Two
(v) $(\angle \mathrm{A}, \angle \mathrm{B})$ or $(\angle \mathrm{B}, \angle \mathrm{C})$ or $(\angle \mathrm{C}, \angle \mathrm{D})$ or $(\angle \mathrm{D}, \angle \mathrm{A})$
(vi) $(\angle \mathrm{A}, \angle \mathrm{C})$ or $(\angle \mathrm{B}, \angle \mathrm{D})$
(vii) Four
(viii) Two