Back
Course / Category - 10th NTSE

Available Online Courses for selected Class / Category

NTSE

10th NTSE

BASIC

Free
 

Join Now Syllabus

Self Learning

Free Topics

(Click here to know About SELF LEARNING)

MOCK TESTS

Few Available

(Click here to attempt Free Mock Test)

Concepts Learning Progress

Available

Course Progess

Self Learning Progress

Report Card

Revision / Exam Preparation

Theory Notes

Question Bank

Subjects Related Concepts

Test Generator

Free Topics

Reports

Available as Required.

VIDEOS

Few Available

Join Now Syllabus

NTSE

10th NTSE

Self Learning

17200 ₹12000 +
Taxes

Join Now Syllabus

Self Learning

Available

(Click here to know About SELF LEARNING)

MOCK TESTS

65

(Click here to attempt Free Mock Test)

Concepts Learning Progress

Available

Test Generator

Syllabus / Topic Test

Solution and Detailed Analysis

Course Progess

Self Learning Progress

Report Card

Revision / Exam Preparation

Theory Notes

Test Generator

Subjects Related Concepts

Self Learning

Videos

Self Learning Exams

Practice

Self Learning - At Own Pace

Question Answers with Explaination

Reports

Question-wise Analysis

Strong, Moderate and weak Concepts

Remedial Tests for Weak Concepts

Achievements - Month/Subject & Subject / Month

Self Study Detail

Graphical View

Your Rankings - Month / Subject & Subject / Month

VIDEOS

799

SUBJECTS

Maths, Physics, Chemistry, Biology, English, History, Democratic Politics, Geography, Economics, Verbal Reasoning, Non Verbal Reasoning, Vedic Maths

Join NowSyllabus
(You can also select a particular Subject or Sub-Topic as per your choice to start with. Please sign-up and proceed. Selection of Subject and Sub-Topics will appear in Purchase section after Login. To sign-up, click here.)

Concept Detail
Maths / Coordinate Geometry / Area of Triangle Using Coordinate
(A Brief Glimpse of ABHYAS Content - Have aLook !!!!)

Area of Triangle Using Coordinate

We know that area of the trapezium ABCD whose two parallel sides are AB and DC and the distance between parallel sides is h, is given by

      large frac{1}{2}(AB+DC)h

Let ABC be a triangle with vertices large A(x_{1},y_{1}),B(x_{2},y_{2})  and large C(x_{3},y_{3}) as shown in figure below.

Draw the ordinates AL, CM and BN.

Note that area of triangle ABC = Area of trapezium ALNB + Area of trapezium ACML - Area of trapezium BCMN

= large frac{1}{2}(AL+BN)LN+frac{1}{2}(AL+CM)LM-frac{1}{2}(BN+CM)MN

But   large AL=y_{1},BN=y_{2},CM=y_{3}

  large LM=OM-OL=x_{3}-x_{1},MN=OM-ON=x_{3}-x_{2}

large and;LN=OL-ON=x_{1}-x_{2}

large therefore  Area of triangle ABC

  large =frac{1}{2}(y_{1}+y_{2})(x_{1}-x_{2})+frac{1}{2}(y_{1}+y_{3})(x_{3}-x_{1})-frac{1}{2}(y_{2}+y_{3})(x_{3}-x_{2})

large =frac{1}{2}[(y_{1}+y_{2})x_{1}-(y_{1}+y_{2})x_{2}+(y_{1}+y_{3})x_{3}-(y_{1}+y_{3})x_{1}-(y_{2}+y_{3})x_{3}+(y_{2}+y_{3})x_{2}]large =frac{1}{2}[(y_{1}+y_{2})x_{1}-(y_{1}+y_{3})x_{1}+(y_{2}+y_{3})x_{2}-(y_{1}+y_{2})x_{2}+(y_{1}+y_{3})x_{3}-(y_{2}+y_{3})x_{3}]

large =frac{1}{2}[x_1(y_{1}+y_{2}-y_{1}-y_{3})+x_2(y_{2}+y_{3}-y_{1}-y_{2})+x_3(y_{1}+y_{3}-y_{2}-y_{3})]

large =frac{1}{2}[x_{1}(y_{2}-y_{3})+x_{2}(y_{3}-y_{1})+x_{3}(y_{1}-y_{2})]

How to obtain Area of a Triangle?

Rules to write down the area of a triangle whose vertices are given:

(i) Write down the coordinates of the vertices in order in two columns, repeating at the end the coordinates at the head,

(ii) draw diagonal arrows as in cross multiplication, and draw two vertical lines to enclose the two columns, and

(iii) prefix the factor large frac{1}{2}, thus getting

Simplification

Take the products of each row and the next crossway, putting the minus sign between them, as in cross multiplication, add the results, and multiply the sum by large frac{1}{2}, thus getting

 large Delta =frac{1}{2}[x_{1}y_{2}-x_{2}y_{1}+x_{2}y_{3}-x_{3}y_{2}+x_{3}y_{1}-x_{1}y_{3}]

Sign of Area:  The areas of the triangles ABC and ACB are opposite in sign. In numerical cases, we usually ignore the sign of the area and take the absolute value of the area of the triangle as the final result.

Thus, we should write as follows:

 area; Delta ABC=frac{1}{2}left | x_{1}(y_{2}-y_3)+x_{2}(y_{3}-y_{1})+x_{3}(y_{1}-y_{2}) right |

That is, brackets in formula (1) have been replaced by the absolute value sign, large parallel,

Illustration: Find the area of the triangle whose vertices are (3,8),(7,2) and (-1,1).

Solution: The area of the triangle whose vertices are (3,8),(7,2),(-1,1) is

      large Delta= frac{1}{2}left | 6-56+7-(-2)-8-3 right |

           large =frac{1}{2}left | 6-56+7+2-8-3 right |=frac{1}{2}left | -52 right |

         = 26 sq. units


A Brief Look
 
Course Progress PANEL
Student can view their progress from this panel.
Self Study
Student can learn from Self Study panel. Concept notes and Video will appear their to learn concept. Exam will be held on the basis of concepts learn.
Exam Evaluation PANEL
Detailed Exam Analysis for Offline and online exams will be Available in Student dashboard. Offline exams will be held for in-campus students only.
Class Notes PANEL
Student can view / download Class Notes assigned to them. Request can also be sent for elapsed Notes.
REPORT CARD
Report Card of each student is visble in Student Panel for WISE-FA, WISE-PT, WISE-Testing, Written Exams, Attendance, etc.
STUDENT PANEL
Ranking amongst the students of the class are visible at any time. Students rank will automatically based on the exams given by the students and score.
SELF LEARNING PANEL
Self Learning panel to know topics/concepts read and exams given. Detail analysis provided to students for exams given. Remedial papers will be generated on student choice for Weak Concepts.
TEST GENERATOR
Test generator to generate test for concepts taught and pending.
STUDENT DASHBOARD
To know Online and Offline exams given / pending with graphical view.
Want Help?
Powered by ABHYAS ChatBOT.

What describes you best?
I am a School Owner
I want to appear for Govt. Exams
Minimize