# Area and Volume Questions

## What is the Formula for Circumradius ?

Solution  : Circumradius Formula (R) = $$abc\over 4\Delta$$ where R = radius of circumcircle described about a given triangle with sides a, b, c. $$\Delta$$ = $$\sqrt{s(s – a)(s – b)(s – c)}$$ and s = $$a + b + c\over 2$$ where a, b and c are the sides of triangle.

## What is the Formula for the Inradius ?

Solution : Inradius Formula (r) = $$\Delta\over s$$ Where r = radius of the circle inscribed in a given triangle $$\Delta$$ = area of the given triangle $$\Delta$$ = $$\sqrt{s(s – a)(s – b)(s – c)}$$ s = half perimeter of the given triangle s = $$a + b + c\over 2$$  for all a, …

## Find the total surface area of hemisphere of radius 10cm ?

Solution : Here radius = 10 cm We know that the surface area of hemisphere = $$3 \pi r^2$$ = $$3 \times 3.14 \times 10 \times 10$$ = 942 $$cm^2$$

## What should be the height of the conical tent ?

Question : In a marriage ceremony of her daughter Poonam, Ashok has to make arrangements for the accommodation of 150 persons. For this purpose, he plans to build a conical tent in such a way that each person has 4 sq. meters of the space on ground and 20 cubic meters of air to breath. …

## The inner diameter of a cylindrical wooden pipe is 24 cm and its outer diameter is 28 cm. The length of the pipe is 35 cm. Find the mass of the pipe, if 1 $$cm^3$$ of wood has a mass of 0.6 g.

Solution : Inner Radius (r) = $$24\over 2$$ = 12 cm Outer Radius (R) = $$28\over 2$$ = 14 cm Height of Pipe = 35 cm Volume = $$\pi (R^2 – r^2) h$$ = $$\pi \times 52 \times 35$$ = 5720 $$cm^3$$ Mass of 1 $$cm^3$$ wood = 0.6 kg Mass of 5720 $$cm^3$$ wood …

## What is the Formula for Volume of Cuboid ?

Solution : The formula for volume of cuboid of length l, breadth b and height h is $$lbh$$. Read Post : Formula for Volume of cuboid – Derivation & Example Similar Questions What is the Formula for Surface Area of Cylinder ? What is the Formula for Surface Area of Cube ? What is the …

## What is the Formula for Surface Area of Cube ?

Solution : The formula for the total suface area of cube of side a is $$6a^2$$. And the formula for the lateral surface area of cube is $$4a^2$$. Read Post : Formula for Surface Area of Cube – Derivation & Example Similar Questions What is the Formula for Volume of Cuboid ? What is the …

## What is the Formula for Surface Area of a Cuboid ?

Solution : The formula for surface area of a cuboid of length l, breadth b and height h is 2(lb + bh + hl). This is the total surface area of cuboid. The lateral surface area of cuboid is 2(l + b)h. Read Post : Formula for Surface Area of Cuboid – Derivation & Example …