Sine, Cosine Rule & Area of TrianglesCambridge IGCSE Maths: Subtopic test
10 questions, 26 marks
Cambridge IGCSE Maths
Sine, Cosine Rule & Area of Triangles
Total 26 marks
Name
Class
Date
- 1A gardener is designing a triangular flower bed ABC. Angle A = 40 degrees, angle B = 65 degrees, and the side (opposite angle A) = 8 cm on the scale plan.(a)Find angle C.[1 mark]
- A65 degrees
- B70 degrees
- C80 degrees
- D75 degrees
(b)Using the sine rule, find the length of side (opposite angle B), correct to 1 decimal place.[1 mark]- A10.3 cm
- B12.3 cm
- C11.3 cm
- D9.3 cm
(c)Using the sine rule, find the length of side (opposite angle C), correct to 1 decimal place.[1 mark]- A11.0 cm
- B12.0 cm
- C13.0 cm
- D10.5 cm
Total for question 1: 3 marks
- 2Two hikers set off from a campsite C. Hiker P walks 6 km from C on one bearing and hiker Q walks 9 km from C on another bearing. The angle between their two paths at the campsite is 50 degrees.(a)Use the cosine rule to calculate the direct distance PQ between the two hikers, correct to 1 decimal place.[2 marks](b)Using the sine rule and your answer to part (a), find angle CPQ (the angle at hiker P's position), correct to 1 decimal place.[2 marks]
Total for question 2: 4 marks
- 3A landscaper is quoting for turf on a triangular plot of land ABC, where AB = 15 m, AC = 11 m and angle A = 55 degrees.(a)Calculate the area of the plot, correct to 1 decimal place.[3 marks](b)Use the cosine rule to calculate the length of BC, correct to 1 decimal place.[3 marks]
Total for question 3: 6 marks
- 4A surveying team is mapping a triangular plot of land PQR for a new sports field. They measure PQ = 20 m, QR = 14 m, and angle QPR = 35 degrees.(a)Show that there are two possible values for angle PRQ, and find both values, correct to 1 decimal place.[4 marks](b)Given that angle PRQ is the obtuse value found in part (a), find angle PQR and hence use the sine rule to find the length PR, correct to 1 decimal place.[4 marks](c)Using PQ = 20 m, PR = 8.3 m (from part (b)) and angle QPR = 35 degrees, calculate the area of triangle PQR, correct to 3 significant figures.[5 marks]
Total for question 4: 13 marks
End of questions