## Maths Formulas for Class 8

Maths is one of the most important subjects in school. It is a subject that teaches us how to think logically and solve problems. However, many students find maths difficult and are often put off by the long list of formulas they have to memorize for each class. In this article, we will share with you some tips on how to make learning maths formulas easier and less daunting for **class 8** students.

## What is a Math Formula?

A math formula is a statement that shows the relationship between two or more things. Formulas are often used in mathematics to calculate things. For example, the formula for the area of a rectangle is A = lW, which means that the area of a rectangle is equal to its length times its width.

Formulas can also be used in other subjects, such as chemistry and physics. In these subjects, formulas are used to calculate things like the speed of an object or the amount of energy in a substance.

There are many different types of formulas. Some formulas are very simple, while others are very complex. Some formulas are used all the time, while others are only used occasionally.

## Why are Math Formulas Important?

There are a few reasons why math formulas are important. First, they provide a concise way to express complex relationships between numbers. Second, they can be used to solve problems. Third, they can be used to make predictions. Fourth, they can be used to derive other formulas. Lastly, they can be used to verify results.

Math formulas are concise because they use a limited number of symbols to express a relationship. For example, the formula for the area of a rectangle is A = lW. This formula expresses the relationship between the length (l) and width (W) of a rectangle and its area (A). The formula is concise because it uses only three symbols.

Math formulas can be used to solve problems. For example, the formula for the area of a rectangle can be used to solve problems such as finding the dimensions of a rectangular box given its volume.

Math formulas can also be used to make predictions. For example, the formula for the perimeter of a rectangle can be used to predict the length of a piece of string that will just fit around the circumference of a circular object.

Lastly, math formulas can be used to derive other formulas. For example, the formula for the circumference

## The Different Types of Math Formulas

There are many different types of math formulas. Some of the most common include algebraic formulas, geometric formulas, and trigonometric formulas.

Algebraic formulas are used to solve equations. These equations can be linear, quadratic, or polynomial equations. Geometric formulas are used to calculate the properties of shapes. These shapes can be two-dimensional or three-dimensional. Trigonometric formulas are used to calculate angles and lengths in triangles.

Each type of math formula has its own specific purpose. However, all math formulas are designed to help us solve problems.

## How to Use Math Formulas

There are a few things to keep in mind when using math formulas. First, make sure you understand the formula and what it is trying to calculate. Second, plug in the appropriate values for the variables in the formula. Third, perform the calculations and simplify the result as needed.

Let’s take a look at an example. Suppose we want to use the formula for finding the area of a rectangle, A = lw. In this formula, A represents the area of the rectangle, l represents the length, and w represents the width. To use this formula, we first need to determine what values we know. In this case, we know the length and width of the rectangle. We can plug these values into the formula and calculate the area.

length (l) = 5 feet

width (w) = 3 feet

area (A) = length (l) * width (w)

area (A) = 5 feet * 3 feet

area (A) = 15 square feet

## List of Important Class 8 Math Formulas :

- Additive inverse of rational number: a/b = -b/a
- Distributivity a(b – c) = ab – ac
- Multiplicative Inverse of a/b = c/d , if a/b × c/d = 1
- Probability of the occurrence of an event = Number of outcomes that comprise an event/ Total number of outcomes
- Compound Interest formula = Amount – Principal, Amount in case the interest is to be calculated annually = Principal ( 1 + Rate/100)
^{n}, where ‘n’ is the time period. - (a + b) (a – b) = a
^{2}– b^{2} - (a – b)
^{2}= a^{2}– 2ab + b^{2} - Euler’s Formula: For any polyhedron, Number of faces + Number of vertices – Number of edges = 2
- Volume of a Sphere = (4/3) π r
^{3} - Volume of a Cone = (1 / 3 )πr
^{2}h

### Class 8 Rational Numbers Math Formulas

Integers, real numbers, natural numbers, whole numbers, fractional numbers and prime and composite numbers are types of rational numbers. The concept of rational number will help students understand that they are different from the rest of the types of arithmetic.

Rational numbers are numbers that have the form of a/b, where b ≠ 0. Rational numbers have following properties:

- Additive Identity states (a ⁄ b + 0) = (a ⁄ b)
- Multiplicative Inverse states (a ⁄ b) × (b/a) = 1
- Multiplicative Identity states (a ⁄ b) × 1 = (a/b)

### Geometry Solid Shapes Class 8 Math Formulas

- Curved Surface Area of a Cone = 1 /2 × l × 2πr = πrl, where ‘r’ is its base radius and ‘l’ its slant height. ‘l’ = √(r
^{2}+ h^{2}) - Volume of a Hemisphere = (2/3) πr
^{3} - Volume of a Cuboid = Base Area × Height = Length × Breadth × Height
- Volume of a Sphere = (4/3) π r3
- Volume of a Cone = (1 / 3 )πr
^{2}h

### Exponents Formulas for Class 8 Maths

- Law of Zero Exponent: a
^{0}= 1 - Law of Quotient: a
^{m}/a^{n}= a^{m – n} - Law of Product: a
^{m}× a^{n}= a^{m + n} - Law of Power of a Power: (a
^{m})^{n}= a^{mn} - Law of Power of a Product: (ab)
^{m}= a^{m}b^{m} - Law of Power of a Quotient: (a/b)
^{m}= a^{m}/b^{m}

### Class 8 Algebra Formulas

- (a + b)
^{2}= a^{2}+ 2ab + b^{2} - (a + b) (a – b) = a
^{2}– b^{2} - (a – b)
^{2}= a^{2}– 2ab + b^{2}

## Conclusion

There is no denying that math’s can be difficult, but with the right formulas at your disposal, it can actually be quite simple. We hope that our list of maths formulas for class 8 students has been helpful and that you feel more confident in tackling your next maths test. Do you have any favorite formulas? Let us know in the comments below!