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We use mensuration every day. Right from the milk in our house coming in specific volumes to all the furniture with cuboids stacked together, everything has an important role to play in our life. Being so closely related, we must learn about its characteristics and the formulas associated with them. The terms in mensuration, help us to imagine on what basis the formulas are applied. There is a difference in the terms of mensuration used in the 2D figures and the 3D figures as there is a change in the number of planes involved in the shape. The understanding required for the formula is seen in understanding the terminologies used in them.

Important Terms in Mensuration

  • Area – Area can be defined as the region occupied by a closed geometric figure. It is applicable for both 2D and 3D figures. It is measured in the squared units of length and defined by the letter ‘A’
  • Length – Length can be defined as the measure of the distance between two points. It is applicable for both 2D and 3D figures. It is measured in mm, cm, m, and km in the standard format
  • Breadth – Breadth is the width of a 2D or a 3D figure. It is generally smaller in distance from the length and it uses similar units of measurement as length

Height – Height is the vertical distance from the base to the top of a 3D figure

  • Volume – Volume is a term exclusively for 3D figures. In simple terms, the volume gives us an idea about the total space a 3D figure holds
  • Perimeter – This term is used for 2D figures, it is a summation of the length and breadth of the figure. It gives us the measurement of the boundary of a 2D figure
  • Surface area – The surface area is an area of the surface that a 3D figure has. It is the area that takes for covering a 3D figure’s surface 
  • Curves surface area – Some 3D figures have curved surfaces instead of sharp edges. A curved surface area is a surface area of only the curved surfaces of a 3D shape except for the circular top and base
  • Lateral surface area – Lateral area covers all of the 3D objects except the top and base of the object
  • Total Surface area – Total surface area is the summation of surface areas of the whole 3D object including the top and base
  • Squared Unit – Such units are used in the measurement of area. They are used when two similar units are multiplied to get the answer as per the formula
  • Cubic unit – Such units are used in the measurement of volume. They are used when three similar units are multiplied to get the answer as per the formula

Mensuration Formulas

2D Figures

3D Figures

 

Characteristics of Mensuration

  • Mensuration has two types depending on the number of planes the shape is associated with, 2D figures, and 3D figures
  • The terms used in both such figures are different as there is a difference in the number of planes associated, eg. area and volume
  • New terms are introduced in the formula for 3D figures such as surface area
  • Often there is a combination of formulas used in creating new formulas due to their geometric structure

Conclusion

It becomes easier to understand a formula if we understand the terminologies well. It will be more helpful if we imagine and understand the terminologies. This will help us understand why particular terms are used in a formula. While deriving these formulas, these terminologies were considered to get a correct and the most accurate formula. Mensuration is the simplest topic in mathematics if we thoroughly understand the terms as well as the formulas for each figure. It is important to not just remember the formula but understand it. The formulas are not 100% efficient but they hold almost true in most cases.