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
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CBSE X Related Questions

1.
If \( \alpha, \beta \) are the zeroes of the quadratic polynomial \( px^2 + qx + r \), then find the value of \( \alpha^3\beta + \beta^3\alpha \).
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2.
If \(\alpha, \beta\) are the zeroes of the polynomial \(p(x) = x^2 - 3x - 1\), then find the value of \(\frac{1}{\alpha} + \frac{1}{\beta}\).
View Solution
3.
In the given figure, \(AB \parallel DE\) and \(AC \parallel DF\). Show that \(\triangle ABC \sim \triangle DEF\). If \(BC = 10\) cm, \(EB = CF = 5\) cm and \(AB = 7\) cm, then find the length DE.
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4.
\(ABCD\) is a parallelogram such that \(AF = 7 \text{ cm}\), \(FB = 3 \text{ cm}\) and \(EF = 4 \text{ cm}\), length \(FD\) equals
- \(\frac{21}{4} \text{ cm}\)
- \(\frac{28}{3} \text{ cm}\)
- \(\frac{12}{7} \text{ cm}\)
- \(5.5 \text{ cm}\)
View Solution
5.
The value of \(p\) for which roots of the quadratic equation \(x^{2} - px + 6 = 0\) are rational, is
- \(1\)
- \(-5\)
- \(25\)
- \(\sqrt{5}\)
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6.
If the pair of linear equations : \( a_1x + b_1y + c_1 = 0 \) and \( a_2x + b_2y + c_2 = 0 \) is consistent and dependent, then
- \( \frac{a_1}{a_2} \neq \frac{b_1}{b_2} \)
- \( \frac{a_1}{a_2} = \frac{b_1}{b_2} = \frac{c_1}{c_2} \)
- \( \frac{a_1}{a_2} = \frac{b_1}{b_2} \neq \frac{c_1}{c_2} \)
- \( \frac{a_1}{a_2} = \frac{b_1}{b_2} = \frac{c_1}{c_2} \)
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NCERT Solutions for Class 9 Maths Chapter 7: Triangles

NCERT Solutions for Class 9 Mathematics Chapter 7