Take a point $\mathrm{O}$ inside a pentagon $\mathrm{ABCDE}$. Join the point $\mathrm{O}$ with all its vertices. In how many triangles will the pentagon be divided ? Name them.

Draw a quadrilateral. Name the sides, vertices, angles and diagonals of the quadrilateral.

From the following figure, name the pairs of adjacent sides.

From the following figure, name the pairs of opposite sides.

From the following figure, name the pairs of adjacent angles.

From the following figure, name the pairs of opposite angles.