1. A man is climbing a ladder which is inclined to the wall at an angle of 30°. If he ascends at a rate of 2 m/s, then he approaches the wall at the rate of
2. P and Q are two points observed from the top of a building 10√3 m high. If the angles of depression of the points are complementary and PQ = 20 m, then the distance of P from the building is
3. A tree is broken by the wind. If the top of the tree struck the ground at an angle of 30° and at a distance of 30 m from the root, then the height of the tree is
4. A vertical stick 12 cm long casts a shadow 8 cm long on the ground. At the same time, a tower casts a shadow 40 m long on the ground. The height of the tower is
5. The tops of two poles of height 24 m and 36 m are connected by a wire. If the wire makes an angle of 60° with the horizontal, then the length of the wire is
6. If I is the in-centre of ∆ ABC and ∠A=60° , then the value of ∠BIC is
7. In an obtuse-angled triangle ABC, ∠A is the obtuse angle and O is orthocenter. If ∠BOC=54° then ∠BAC is
8. If the sides of a triangle are in the ratio 3:1 1/4 ∶3 1/4 , then the triangle is
9. If the length of each of two equal sides of an isosceles triangle is 10 cm. and the adjacent angle is 45°, then the area of the triangle is
10. For an equilateral triangle, the ratio of the in radius and the outer-radius is
