$D$ is a point on the side $BC$ of a $\triangle ABC$ such that $AD$ bisects $\angle BAC$. Then

If $AB = QR$,$BC = PR$,and $CA = PQ$,then

$O$ is a point in the interior of a square $ABCD$ such that $\triangle OAB$ is an equilateral triangle. Show that $\triangle OCD$ is an isosceles triangle.

Is it possible to construct a triangle with lengths of its sides as $4 \, cm, 3 \, cm$ and $7 \, cm$? Give reason for your answer.

If $\Delta ABC \cong \Delta RPQ$ and the perimeter of $\Delta ABC$ is $18 \, cm$,then the perimeter of $\Delta PQR$ is $cm$.

The sum of any two sides of a triangle is $\ldots \ldots \ldots$ than the third side.