The sides of a triangle are in the ratio 3 : 4 : 5. The measure of the largest angle of the triangle is

A hemispherical tank full of water is emptied by a pipe at the rate of 7.7 litres per second. How much time (in hours) will it take to empty $$2\over 3$$ part of the tank, if the internal radius of the tank is 10.5 m?

The area of two equilateral triangles are in the ratio 25 : 36. Their altitudes will be in the ratio : 

A cylindrical roller made of iron is 1.2 m long. Its internal radius is 24 cm and thickness of the iron sheet used in making the roller is 15 cm. What is the mass (in kg) of the roller, if 1 cm³ of iron has 8 g mass?

A circle circumscribes a rectangle with sides 16 cm and 12 cm. What is the area of the circle?

The radius of a wire is decreased to one third. If volume remains the same, length will increase by :

The curved surface area of a cylinder is five times the area of its base. Find the ratio of radius and height of the cylinder.

The base and altitude of a right angled triangle are 12 cm and 5 cm respectively. The perpendicular distance of its hypotenuse from the opposite vertex is