1. Law of sines is:
(A) a/sinB = b/sinA = c/sinC
(B) a/sinA = b/sinB = c/sinC
(C) a/sinB = b/sinA = c/sinC
(D) a/sinB = b/sinC = a/sinA
2. In a triangle ABC ∠A = 70°, ∠B = 60°, then ∠C is:
(A) 30°
(B) 40°
(C) 50°
(D) 60°
3. When angle of elevation is viewed by an observer, the object is:
(A) Above
(B) Below
(C) At the same level
(D) None of these
4. If b = 2, A = 30°, B = 45°, then a is equal to:
(A) 2
(B) √2
(C) √3/2
(D) 2/3
5. If a = 2, b = 2, A = 30°, then B is:
(A) 45°
(B) 30°
(C) 60°
(D) 90°
6. If in a triangle ABC, the sides b, c and angle A are given, then side a is:
(A) a² = b² + c² + 2bc cosA
(B) a² = b² – c² – 2ab cosA
(C) a² = b² + c² – 2bc cosA
(D) a² = b² – c² + 2ab cosA
7. In a triangle ABC, the law of cosine is:
(A) cosA = (b² + c² + a²)/2bc
(B) cosA = (b² + c² – a²)/2bc
(C) cosA = (b² + c² + a²)/2ab
(D) cosA = (b² + c² – a²)/2ac
8. If in a triangle ABC, b = 2, c = 2, A = 60°, then side a is:
(A) 2
(B) 3
(C) 4
(D) 5
9. If in a triangle ABC, a = 1, b = 2, C = 60°, then side c is:
(A) 2
(B) √3
(C) 1
(D) 3
10. If in a triangle ABC, b = 2, c = 3, a = 1, then cosA is:
(A) 1
(B) 2
(C) 3
(D) 1
11. If in a triangle ABC, a = 3, b = 4, c = 2, then cosC is:
(A) 1/2
(B) 3/4
(C) 7/8
(D) 3
12. If b sinC = c sinB, then a sinB is equal to:
(A) c sinA
(B) b sinC
(C) b sinA
(D) b sinB
13. In a right triangle if one angle is 30°, then the other will be:
(A) 45°
(B) 50°
(C) 60°
(D) 75°
14. In a right triangle if one angle is 45°, then the other will be:
(A) 45°
(B) 50°
(C) 60°
(D) 75°
15. If B = 90°, b = 2, A = 30°, then side a is:
(A) 4
(B) 3
(C) 2
(D) 1
16. If C = 90°, a = 1, c = 2, then angle A is:
(A) 90°
(B) 60°
(C) 45°
(D) 30°
17. If C = 90°, b = 1, c = 2, then side a is:
(A) 1
(B) √3
(C) 2
(D) 3
18. If C = 90°, b = 1, c = 2, then angle A is:
(A) 15°
(B) 30°
(C) 45°
(D) 60°
19. The distance of a man from the foot of a 100m tower, if angle of elevation is 30°, is:
(A) 50 m
(B) 100 m
(C) 150 m
(D) 200 m
20. A pilot at a height of 50m measures angle of depression of a tower 30°, distance from tower is:
(A) 50 m
(B) 25 m
(C) 20 m
(D) 10 m