NCERT Solutions for Class 9 Maths Chapter 7: Triangles

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The NCERT Solutions for class 9 Maths Chapter 7 Triangles are included in the article below. A triangle is a closed shape with three angles, three sides, and three vertices. It has two basic formulas that help us to determine its area and perimeter.

Class 9 Maths Chapter 7 Triangles belong to Unit 4 Geometry which has a weightage of 27 marks in the Class 9 Maths Examination. Class 9 Maths Chapter 7 has the following important concepts:

Download: NCERT Solutions for Class 9 Mathematics Chapter 7 pdf

NCERT Solutions for Class 9 Mathematics Chapter 7

The Chapter 7 Class 9 Maths are given below:

Important Topics in Class 9 Maths Chapter 7 Triangles

Important Topics in Class 9 Maths Chapter 7 Triangles are elaborated below:

Area of Triangles

The area of a triangle is the space confined within the three sides of a triangle. For calculating its area, the base length and the height of the triangle are required.

Example: What is the formula to determine the area of a triangle?

Solution: The formula to determine the Area of a Triangle is:
Area of triangle = ½ (base x height) = ½ b x h

Perimeter of Triangles

The perimeter of a respective triangle can be defined as the sum of three sides of the triangle. For example, if a triangle has sides ABC, then the perimeter of it would be (AB + BC + AC).

Perimeter of Scalene Triangle: A + B + C
Perimeter of Iosceles Triangle: 2A + B
Perimeter of Equilateral Triangle: 3A

Congruency of Triangles

If two triangles have the same shape and size, then they are found congruent to one another.

Example: List all the followed criteria for congruency in a triangle.

Solution: The criteria of conguency in Triangles are:

SSS (side-side-side) congruency
SAS (side-angle-side) congruency
ASA (angle-side-angle) congruency
AAS (angle-angle-side) congruency
RHS (right angle-hypotenuse-side) congruency

NCERT Solutions for Class 9 Maths Chapter 7 Exercises:

The detailed solutions for all the NCERT Solutions for Triangles under different exercises are:

Also Read:

Unit Related Topics
Triangle Theorems	Pythagoras Theorem	Questions on Triangles
Mid Point Theorem	Isosceles Triangle	Class 9 Maths Chapter 7 Triangles MCQs
Sides of a Triangle	Similar Figures	Properties of Triangles

Check out:

Math Study Guides
Maths Important Formulas	Maths MCQs	Comparison Articles in Maths
Difference Between Topics in Maths	Math Study Material	Algebra
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Math Formula	NCERT Solutions for Class 9 Maths	Geometry

CBSE X Related Questions

1.
A bag contains 25 balls. Some of them are yellow and others are green. One ball is drawn at random. If probability of getting a green ball is $3/5$, then find the number of yellow balls.
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2.
In the given figure, $AB \parallel DE$ and $AC \parallel DF$. Show that $\Delta ABC \sim \Delta DEF$. If $BC = 10\text{ cm}$, $EB = CF = 5\text{ cm}$ and $AB = 7\text{ cm}$, then find the length $DE$.
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3.
Two water taps together can fill a tank in $8\frac{8}{9}$ hours. The tap of larger diameter takes 4 hours less than the smaller one to fill the tank separately. Find the time in which each tap can separately fill the tank.
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4.
If the zeroes of a polynomial p(x) are $-3$ and 8, then p(x) equals
- $x^2 + 5x - 4$
- $(x + 3) (-x + 8)$
- $a(x^2 + 5x - 24)$
- $x^2 - 24$
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5.
Prove that $14 - 2\sqrt{3}$ is an irrational number, given that $\sqrt{3}$ is irrational.
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6.
An arc of length $2.2\text{ cm}$ subtends an angle $\theta$ at the centre of the circle with radius $2.8\text{ cm}$. The value of $\theta$ is
- $50^\circ$
- $60^\circ$
- $45^\circ$
- $30^\circ$
View Solution

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NCERT Solutions for Class 9 Maths Chapter 7: Triangles

NCERT Solutions for Class 9 Mathematics Chapter 7