The number of diagonals in a hexagon is _____.

In Fig. 2.13, PQ ⊥ RQ, PQ = 5 cm and QR = 5 cm. Then ∆ PQR is

An angle greater than 180° and less than a complete angle is called ______.

A pair of opposite sides of a trapezium are ________.

In Fig. 2.14, points lying in the interior of the triangle PQR are ______, that in the exterior are ______ and that on the triangle itself are ______.