Question 4 - 20 marks This question is based on your work on MU123 up to and including Unit 12. (a) Figure 5 shows a sketch of a triangle, where all side lengths are measured in centimetres. Find the length of the side marked a, giving [3] your answer correct to one decimal place. 710 8.66 cm Figure 5 (b) Triangle DFE has a right angle at E. The length of side FE is 4.6 cm, and the length of side DF is 6.8 cm. Sketch the triangle and find LFDE, giving your answer correct to the nearest degree. [4] (c) Figure 6 shows the triangle ABC, with all side lengths measured in centimetres. B 7.86 cm A 2.94 cm 5.69 cm C Figure 6 i) Find LABC, giving your answer correct to the nearest degree. [5] (ii) Find the area of triangle ABC, giving your answer correct to the nearest square centimetre. [3](d) (i) Convert 76 to radians, leaving your answer in terms of T. [2] (ii) Use your answer from part (d)(i) to find the perimeter of a sector between a circle of radius 7 cm and another circle of radius 12 cm determined by an angle a of 76 - the sector is outlined in a solid black line in Figure 7. Give your answer correct to three significant figures. [3] 12 cm . . . . . . ... ........ Icm . .... ... D..... Figure 7