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In the world of triangles, Heron's Formula is the golden key to the unknown space within the triangle(s). Everyone knows their own ways of finding the area of a triangle as intended, either through the general area triangle formula or the specially intended formula for an Equilateral triangle. Did you ever stop and ask yourself how you would find the area of a triangle if it were of a scalene nature (different lengths for all three sides), and you had zero idea how to find an altitude? That's where we turn to Heron's formula, and it helps us find the triangle's area. Heron's formula can be used in the actual world, and they can help us to figure out the area of irregular plots. This NCERT solutions chapter effectively breaks it down with real examples of questions and makes it understandable.
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Heron’s formula is the poet's way of determining the area of a triangle. Heron's formula is not just important for grade 9 board exams, but also for higher grade tests and competitive exams as well. These Heron's formula class 9 NCERT solutions align with the current guidelines by CBSE for study, and they have been developed by Careers360 teachers with many years of experience in this area. Students can make an effort to solve the exercises in the NCERT textbooks on their own before validating their answers with the well-constructed solutions in Heron's formula class 9. The most current NCERT solutions for Class 9 Maths not only deal with different types of triangles, but they also take the concept further to quadrilateral problem situations in the real world. An added benefit of the NCERT Solutions for Class 9 materials is to help students apply the formula correctly, especially under test conditions, although the application-based or word problems can also become test questions.
Class 9 Maths chapter 12 Question Answer: Exercise: 12.1 |
Answer:
Given: The Perimeter of the equilateral triangle is 180 cm.
Therefore, each side of the triangle is:
Now, calculate the semi-perimeter:
Use Heron's Formula to find the area, that is:
Area
Answer:
From the figure,
Let the sides of the triangle be:
a = 122m, b = 120m and c = 22m
Therefore, the semi-perimeter,
Thus, Area ( using Heron's formula ):
Given the rent for 1 year (i.e., 12 months) per square meter is Rs. 5000.
Answer:
We are given the sides of the triangle, which are:
a = 15 m, b = 11m and c = 6m
So, the semi-perimeter of the triangle will be:
Therefore, the area painted in colour is:
Question 4: Find the area of a triangle, two sides of which are 18 cm and 10 cm, and the perimeter is 42 cm.
Answer:
Given the perimeter of the triangle is 42 cm and the lengths of two sides,
So,
Thus, the semi-perimeter of the triangle will be:
Therefore, the area given by the Heron's Formula will be,
Question 5: Sides of a triangle are in the ratio of 12 : 17 : 25, and its perimeter is 540 cm. Find its area.
Answer:
Given the sides of a triangle are in the ratio of 12 : 17 : 25 and its perimeter is 540 cm.
Let the length of one side of the triangle to be
Then, the remaining two sides be
Thus, by the given perimeter,
Perimeter
Therefore, the sides of the triangle are:
The semi-perimeter of the triangle is:
Therefore, using Heron's Formula, the area of the triangle is:
Answer:
Given, the perimeter of an isosceles triangle is 30 cm and the length of the sides which are equal is 12 cm.
Let the third side length be 'a cm '.
Then, Perimeter
So, the semi-perimeter of the triangle is:
Therefore, using Heron's Formula, the area of the triangle is:
Question: Find the area of a triangle whose sides are 9 cm, 10 cm, and 17 cm using Heron’s formula.
Answer:
Let the sides be
The topics discussed in the NCERT Solutions for class 9, chapter 10, Heron's Formula, are:
Where ' s ' is the semi-perimeter, and ' a ', ' b ', and ' c ' are the lengths of its sides.
Area
For an equilateral triangle with side length 'a':
Its perimeter is given by: Perimeter = 3a units.
The altitude (height) of an equilateral triangle is equal to
Altitude
The area of an equilateral triangle is equal to
Area
These steps will assist students in confidently handling NCERT Class 9 Heron's Formula questions.
1. Memorise the Heron’s Formula: Students need to remember the standard formula, which states Area equals the square root of semi-perimeter times its difference with each side. The formula uses "s" to denote the semi-perimeter of a triangle.
2. Calculate semi-perimeter accurately: The calculation of
3. Check if a triangle is valid: The triangle inequality rule should be used to verify triangle feasibility before you implement the formula.
4. Work with different triangle types: Apply Heron’s formula on various triangle shapes, including scalene, isosceles and right-angled to enhance your understanding of the concept.
5. Special attention must be given when simplifying square roots: Preparing the value inside the square root for calculation before extracting the root will reduce errors, particularly when working with irrational numbers.
6. Extend to real-world problems: When solving problems about land plots or uneven quadrilaterals, apply Heron’s rule by dividing the shape into two triangles.
We at Careers360 compiled all the NCERT class 9 Maths solutions in one place for easy student reference. The following links will allow you to access them.
Students can also check these subject-wise solutions. These solutions have explained every step and are written in very easy language.
The following links can be used to find the latest CBSE syllabus and a reference math book. These are very useful study materials to do well in the exam.
Area of a Triangle – by Heron’s Formula and Application of Heron’s Formula in finding Areas of Quadrilaterals are two important topics of this chapter. Students can prioritize important topics from the NCERT syllabus and study accordingly to score well in exams. for ease you can study heron's formula class 9 pdf both online and offline mode.
Here are the rephrased key benefits of NCERT Solutions for Class 9 Maths Chapter 12:
The solutions for each exercise within the chapter are easily accessible for students to refer to.
The solutions are designed with graphs and illustrations that aid in providing a clear understanding of the mathematical concepts.
The solutions are meticulously prepared by the expert team at Careers360, with a strong emphasis on accuracy.
NCERT solutions are helpful for students if they are not able to solve the NCERT problems on their own. These solutions also provide detailed explanations, giving students conceptual clarity.
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