Heron's Formula Class 9th Notes - Free NCERT Class 9 Maths Chapter 12 Notes - Download PDF

# Heron's Formula Class 9th Notes - Free NCERT Class 9 Maths Chapter 12 Notes - Download PDF

Edited By Ramraj Saini | Updated on Apr 21, 2022 01:59 PM IST

## Heron’s Formula class 9 notes:

The Heron’s Formula is the NCERT chapter in which we deal with the area of triangles Egypt's Heron devised a formula for calculating the area of any triangle. Heron's Formula or Hero's Formula is the name given to this formula. The NCERT Class 9 Maths Chapter 12 Notes covers a brief outline of the chapter Heron’s Formula. The main topics covered are What is Triangle, Area of an equilateral triangle, Area of the isosceles triangle, Area of a triangle by heron’s formula in the Heron’s Formula class 9 notes with some FAQs.

The basic equations in the chapter are also covered in the class 9 mathematics chapter 12 notes. All of these concepts are covered in class 9 Heron’s Formula notes. CBSE class 9 maths chapter 12 notes contain important formulas. The class 9 maths chapter 12 notes contains systematic explanations of topics using examples and exercises.

Also, students can refer,

## NCERT Class 9 Maths Chapter 12 Notes

Triangle
A triangle is a closed plane figure that has three sides and three angles.

Triangles are classified into three types

Based on their sides

• Equilateral
• Isosceles
• Scalene

Based on angles

• Acute angled triangle
• Right-angled triangle
• Obtuse angled triangle

Area of a triangle:

Area A = ( 1/2 ) ( base ) ( height )

If the lengths of the triangles' sides are known, we may apply the Pythagoras theorem to find the height of a triangle is equilateral and isosceles triangles.

Area of an equilateral triangle:

A = ( √3 / 4) a2

Area of an isosceles triangle:

A = ( 1 / 4 ) b √ ( 4 a2 - b2 )

## Area of a triangle By Heron’s formula

Heron's formula (also known as Hero's Formula) calculates the area of an ABC given the sides a, b, and c:

For semi perimeter (s) = (a + b + c)/2

Area A = √ [ s ( s - a ) ( s - b ) ( s - c ) ]

This formula can be used to calculate the area of a scalene triangle when the lengths of all of its sides are known.

By Heron's formula, the area of any polygon is calculated.
When one of the diagonal values and the sides of a quadrilateral are known, the area can be computed by breaking the quadrilateral into two triangles and applying Heron's formula.

## Significance of NCERT class 9 maths chapter 12 notes

The notes from Heron's Formula class 9th will help you review the chapter and get a sense of the important points presented.

This NCERT class 9 maths chapter 12 will help students to understand the formulas, statements, and rules in detail.

Class 9 mathematics chapter 12 notes pdf download can be used to study when offline.

NCERT solutions of class 9 subject wise

NCERT Class 9 Exemplar Solutions for Other Subjects:

NCERT Class 9 Notes Chapter wise

 NCERT Class 9th Math Chapter 1 Notes NCERT Class 9th Maths Chapter 2 Notes NCERT Class 9th Maths Chapter 3 Notes NCERT Class 9th Maths Chapter 4 Notes NCERT Class 9th Maths Chapter 5 Notes NCERT Class 9th Maths Chapter 6 Notes NCERT Class 9th Maths Chapter 7 Notes NCERT Class 9th Maths Chapter 8 Notes NCERT Class 9th Maths Chapter 9 Notes NCERT Class 9th Maths Chapter 10 Notes NCERT Class 9th Maths Chapter 11 Notes NCERT Class 9th Maths Chapter 12 Notes NCERT Class 9th Maths Chapter 13 Notes NCERT Class 9th Maths Chapter 14 Notes NCERT Class 9th Maths Chapter 15 Notes

1. Find the area of the Triangle where all sides are equal to a 4 cm as per class 9th maths chapter 12 notes.

As all sides are equal then it must be an equilateral triangle.

So area of an equilateral triangle:

A = ( √3 / 4) a2

; ( √3 / 4) (4)2 = 6.928 cm2

2. Find the semiperimeter of triangle having all side as 1 cm

### For semi perimeter (s) = (a + b + c)/2 ;

So, =(1+1+1)/3

=3/3

=1

3. Write down the Herons Formula?

### For semi perimeter (s) = (a + b + c)/2 ;

So, =(1+1+1)/3

=3/3

=1

4. Is Heron’s formula applicable in all triangles ?

According to notes for class 9 maths chapter 12,   heron’s formula is applicable to all triangles regardless of side lengths.

5. How does the area of a quadrilateral is calculated using Heron’s formula?

Heron’s formula, the area of a quadrilateral is calculated by dividing it into two triangles.

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