6 66 Mathematical Treasurehunt Sine Cosine The area

6. 66 Mathematical Treasure-hunt: Sine & Cosine The area of a triangle is 10 sq cm. The angle between two of the sides of length 6 cm and 8 cm resp. are obtuse. Work out the size of this angle. 2. 96 Mathematical Treasure-hunt: Sine & Cosine In the triangle below work out the value of the area. 3 cm 5 cm 40 1 2

13. 7 Mathematical Treasure-hunt: Sine & Cosine The sides of a triangle are 3, 5 and 7 cm. Show that the largest angle is 120 and find the area. 3 11. 2 Mathematical Treasure-hunt: Sine & Cosine Triangle ABC is such that AB = 4 cm, BC = 6 cm and angle ACB = 36. Find the length AC. 4

6. 50 Mathematical Treasure-hunt: Sine & Cosine A triangle has sides AB = 4. 5 cm, BC = 6. 8 cm and angle ACB = 30. Find the largest angle. 5 22. 3 Mathematical Treasure-hunt: Sine & Cosine From a point A a boat sails due north for 7 km to B. The boat leaves B and moves on a bearing of 100 for 20 km until it reaches C. calculate the distance C from A. 6

101 or 131 Mathematical Treasure-hunt: Sine & Cosine A helicopter flies on a bearing of 080 from A to B where AB = 50 km. It then flies for 60 km to a point C. Given that C is 80 km from A calculate the bearing of C from A. 7 104 Mathematical Treasure-hunt: Sine & Cosine In triangle ABC AB = 5 cm , BC = 6 cm and AC = 10 cm. Calculate the value of the largest angle. 8

128. 5 or 31. 5 Mathematical Treasure-hunt: Sine & Cosine In triangle ABC AB = 9. 3, BC = 6. 2 and AC = 12. 7. calculate the value of the largest angle. 9 108. 4 Mathematical Treasure-hunt: Sine & Cosine The lengths of a triangle are in the ratio 2: 3: 4. calculate the largest angle. 10