Mensuration Class 8 Formulas

Mensuration is an important part of geometry in mathematics. This branch deals with the measure of length, volume, area of various solid and plane figures of geometry. Mensuration class 8 formulas are the formulas related to the perimeter and area of different geometric figures.

List of Mensuration Class 8 Formulas

Here is a brief list of mensuration formulas that are commonly used to solve questions related to solid and plane figures.

• Area of Trapezium = height × (sum of parallel sides)/2
• Area of Rhombus = ½ × d¹ ×  d²; where d¹ ×  d² are the two diagonals of the rhombus
• Area of Special Quadrilateral = ½ × d × (h¹ + h²); where d is the diagonal, and h¹ and h² are the perpendiculars drawn on the diagonals from the vertices.
• Surface area of Cuboid = 2(lb × bh × hl); where l, b and h represent the length, breadth and height of the cuboid.
• Surface area of Cube = 6a²; where a represents the side of the cube.
• Surface area of cylinder = 2πr(r + h); where h represents the height and r represents the radius of the cylinder.
• Volume of Cuboid = l × b × h; where l, b and h represent the length, breadth and height of the cuboid.
• Volume of Cube = a³; where a represents the side of the cube.
• Volume of cylinder = πr²h; where h represents the height and r represents the radius of the cylinder.

Applications of Mensuration Class 8 Formulas

We are surrounded by various shapes and figures in our environment. There are several instances where we come across situations to compute the area, perimeter and volume of shapes. Let us see how mensuration class 8 formulas are applied in the real world.

• Mensuration class 8 formulas are applied in the measurement of agricultural fields and floor areas that are required for purchase/selling transactions.
• The length of the boundary of plots and fields can be calculated using the perimeter formulas.
• Measurement of liquids like packaged milk, oil, or solid edible food items can be done using the formulas given for volume.
• Mensuration formulas can be used to find the volumes and heights that are useful in knowing water levels and amounts in rivers or lakes.
• The surface area formulas in mensuration can be used to estimate the cost of painting houses, buildings etc. .

Tips to Memorize Mensuration Class 8 Formulas

Mensuration class 8 formulas sometimes seem complex to remember due to the unclarity of terms associated with them. Therefore, here are some tips for students to memorize these formulas in much easier ways:

• Mensuration class 8 formulas deal with dimensions of 2-D objects like length, volume, shape, surface area, etc. The students must make sure to understand the meaning of these terms first before moving ahead to memorize the formulas. They can get help from teachers or their friends to get clarity on the same.
• Once they are clear with the terms, they can formulate a story around the formula, or weave the initials of the formula into some word of their choice so as to quickly picture it in front of them. 
• Students can watch the formula visuals on their gadgets to ensure a quick revision whenever they use their mobile or laptop.
• Students should practice a complete set of problems and solved examples provided in the textbook. It will help students to maximize the usage of formulas in different contexts.

Mensuration Class 8 Formulas Examples

Example 1: Calculate the height of a cuboid which has a base area of 180 cm² and volume is 900 cm³

Solution: We know that the formula for calculating the volume of cuboid = base area × height

Therefore, 900 cm³ = 180 cm² × height

So, height of cuboid  = 900/180 = 5 cm

Example 2: Find the surface area of a cube which has a side length of 5 units. 

Solution:

Surface area of Cube = 6a²; here a = 5

Substituting the value in the formula: Surface area of Cube = 6a² = 6 × 52 = 6 × 25 = 150 square units.

Students can download the printable Maths Formulas Class 8 sheet from below: