Two houses are collinear with the base of a tower and are at distance 3 m and 12 m from the base of the tower. The angles of elevation from these two houses of the top of the tower are complementary. What is the height of the tower?
A round balloon of unit radius subtends an angle of 90° at the eye of an observer standing at a point, say A. What is the distance of the centre of the balloon from the point A?
The difference between the area of a square and that of an equilateral triangle on the same base is $1/over4$ $cm^ 2$ . What is the length of side of triangle?
A cone is inscribed in a hemisphere such that their bases are common. If C is the volume of the cone and H that of the hemisphere, then what is the value of C : H?
An obtuse angle made by a side of a parallelogram PQRS with other pair of parallel sides is 150�. If the perpendicular distance between these parallel sides (PQand SR) is 20 cm, what is the length of the side RQ?