MENSURATION

Ø Mensuration is the branch of mathematics which deals with the study of different geometrical shapes, their areas and volume.

Ø In the broadest sense, it is all about the process of measurement.

Ø There are two types of geometric shapes

2D shapes :

1. Square

2. Rectangle

3. Parallelogram

4. Rhombus

5. Triangle

6. Trapezoid

7. Circle

3D shapes:

1. Cube

2. Rectangular Prism(Cuboid)

3. Cylinder

4. Cone

5. Sphere and Hemisphere

6. Prism

7. Pyramid

Ø Formulae :

PROBLEMS

1. A cylindrical drum has a height of 20 cm and base radius of 14 cm. Find its curved surface area and the total surface area.

2. The radius of a conical tent is 7 m and the height is 24 m. Calculate the length of the canvas used to make the tent if the width of the rectangular canvas is 4 m?

3. The radius of a spherical balloon increases from 12 cm to 16 cm as air being pumped into it. Find the ratio of the surface area of the balloons in the two cases.

4. An industrial metallic bucket is in the shape of the frustum of a right circular cone whose top and bottom diameters are 10 m and 4 m and whose height is 4 m. Find the curved and total surface area of the bucket.

5. Calculate the weight of a hollow brass sphere if the inner diameter is 14 cm and thickness is 1mm, and whose density is 17.3 g/.

6. A cone of height 24 cm is made up of modelling clay. A child reshapes it in the form of a cylinder of same radius as cone. Find the height of the cylinder.