**Question:**

In the adjoining figure, *ABCD* is a quadrilateral.

(i) How many pairs of adjacent sides are there? Name them.

(ii) How many pairs of opposite sides are there? Name them.

(iii) How many pairs of adjacent angles are there? Name them.

(iv) How many pairs of opposite angles are there? Name them.

(v) How many diagonals are there? Name them.

**Solution:**

(i) There are four pairs of adjacent sides, namely $(A B, B C),(B C, C D),(C D, D A)$ and $(D A, A B)$.

(ii) There are two pairs of opposite sides, namely $(A B, D C)$ and $(A D, B C)$.

(iii) There are four pairs of adjacent angles, namely $(\angle A, \angle B),(\angle B, \angle C),(\angle C, \angle D)$ and $(\angle D, \angle A)$.

(iv) There are two pairs of opposite angles, namely $(\angle A, \angle C)$ and $(\angle B, \angle D)$.

(v) There are two diagonals, namely $A C$ and $B D$.