In the diagram, lines PQ and RS are parallel. A straight transversal line crosses PQ at point A and RS at point B. The angle QAB is (3x) degrees, and the angle SBA, on the same side of the transversal, is (x + 40) degrees.
Figure (to be drawn): Two parallel lines PQ and RS are crossed by a straight transversal through points A (on PQ) and B (on RS). The angle QAB is marked 3x degrees at A, and the angle SBA is marked (x + 40) degrees at B, on the same side of the transversal. Not drawn to scale.
(a)State the relationship between angle QAB and angle SBA, giving a reason. (1 mark)(1)
(b)Form and solve an equation to find the value of x. (3 marks)(3)
(c)Hence find the size of angle QAB, and state whether it is acute or obtuse. (1 mark)(1)
(Total for Question 16 is 5 marks)