Math : Mensuration

What is Mensuration?

Mensuration is a topic in Geometry which is a branch of mathematics. Mensuration deals with length, Perimeter, area and volume of different kinds of shape- both 2D and 3D.

 

What is a 2D Shape?

A 2D shape is a shape that is bounded by three or more straight lines or a closed circular line in a plane. These shapes have no depth or height; they have two dimensions- length and breadth and are therefore called 2D figures or shapes. For 2D shapes, we measure area (A) and perimeter (P).

What is a 3D Shape?

A 3D shape is a shape that is bounded by a number of surfaces or planes. These are also referred to as solid shapes. These shapes have height or depth unlike 2D shapes; they have three dimensions- length, breadth and height/depth and are therefore called 3D figures.  3D shapes are actually made up of a number of 2D shapes. Also, know as solid shapes, for 3D shapes we measure Volume (V), Curved Surface Area (CSA), Lateral Surface Area (LSA) and Total Surface Area (TSA).

 

Important Terms

 

Perimeter (P) : The length of the boundary of a figure is called its perimeter. In other words, it is the continuous line along the periphery of the closed figure. It is represented by the alphabet P and is measures in cm/ m.

Area (A) : The surface occupied by a given closed shape is called its area. It is represented by the alphabet A and is measured in unit square- m2/ cm2.

Volume (V) : The space that is contained in a three-dimensional shape is called its volume. In other words, it is actually the space that is enclosed in a 3D figure. It is represented by the alphabet V and is measured in cm3/ m3.

Curved Surface Area (CSA) : In solid shapes where there is a curved surface, like a sphere or cylinder, the total area of these curved surfaces is the Curved Surface Area. . The acronym for this is CSA and it is measured in m2 or cm2.

Lateral Surface Area (LSA) : The total area of all the lateral surfaces of a given figure is called its Lateral Surface Area. Lateral Surfaces are those surfaces that surround the object. The acronym for this is LSA and it is measured in m2 or cm2.

Total Surface Area (TSA) : The sum of the total area of all the surfaces in a closed shape is called its Total Surface Area. For example, in a cuboid when we add the area of all the six surfaces we get its Total Surface Area. The acronym for this is TSA and it is measured in m2 or cm2.

 TOPICS   .

·         Rectangles and Squares.

·         Parallelograms.

·         Triangles.

·         Quadrilaterals.

·         Trapeziums.

·         Circles.

·         Cubes and Cuboids

·         Spheres.

·         Cylinder.

·         Cones.

·         Frustum.

·         Miscellaneous.