Question

A unique quadrilateral can be constructed if all its four angles are known.

In constructing ABCD from AB, BC, \angle A, \angle B and \angle C, the vertex D is the point where the rays drawn from A and C meet.

In quadrilateral PQRS, \angle P = 70^\circ, \angle Q = 100^\circ and \angle R = 110^\circ. Find \angle S (in degrees) before starting the construction.

Construct quadrilateral ABCD with AB = 5.5 cm, BC = 4 cm, \angle A = 70^\circ, \angle B = 100^\circ and \angle C = 110^\circ. Write the steps, then measure AD (in cm, to one decimal place).