4 (a) Triangle ABC has sides AB = 8 cm, AC = 7 cm and BC = 12 cm. (i) Use a ruler and compasses to construct triangle ABC. Side AB has been drawn for you. (ii) Measure BACˆ . (b) Calculate the interior angle of a regular 12-sided polygon. (c) The diagram shows a hexagon with two parallel sides and one horizontal line of symmetry. (i) Calculate p . (ii) Calculate q . (d) Trapezium PQRS is similar to trapezium ABCD. AB is parallel to DC and ABtC = 90°. DC = 2AB, BC AB 2 1 = and PQ= 3/4 DC. Given that BC = x cm, find an expression, in terms of x, for the area of PQRS.