In triangle ABC, AB = 7 cm, AC = 9 cm and angle BAC = 60 degrees. Triangle DEF has DE = 7 cm, DF = 9 cm and angle EDF = 60 degrees. (a) Show that triangles ABC and EDF are congruent. (b) Work out the length BC, giving your answer to 3 significant figures.
(a)Show that triangles ABC and EDF are congruent.(2)
(b)Work out BC to 3 significant figures.(3)
(Total for Question 10 is 5 marks)