Class 9 Exam  >  Class 9 Questions  >  Prove that the difference of any two sides of... Start Learning for Free
Prove that the difference of any two sides of a triangle is less than the third side?
Verified Answer
Prove that the difference of any two sides of a triangle is less than ...
Given: ∆ABC,
To Prove:
(i) AC ~ AB <  BC
(ii)    BC ~ AC <  AB
(iii)    BC ~ AB <  AC
Construction: From AC, cut off AD = AB. Join BD.

Proof: In ∆ABD,
AB = AD    | By construction
∴ ∠ABD = ∠ADB    ...(1)
| Angles opposite to equal sides of a triangle are equal
⇒ ∠ABD = ∠2    ...(2)
Now,
Ext. ∠1 >  ∠ABD
| An exterior angle of a triangle is greater than either of its interior opposite angles
⇒    ∠1 >  ∠2    ...(3)
| Using (2)
Ext. ∠2 >  ∠3    ...(4)
An exterior angle of a triangle is greater than either of its interior opposite angles
From (3) and (4),
∠1 >  ∠3
∴ BC >  DC
| Side opposite to greater angle is longer
⇒    BC >  AC - AD
⇒    BC >  AC - AB
| ∵ AD = AB (by construction)
⇒ AC - AB <  BC
Similarly, we can show that
BC ~ AC <  AB
and    BC ~ AB <  AC
This question is part of UPSC exam. View all Class 9 courses
Explore Courses for Class 9 exam

Top Courses for Class 9

Prove that the difference of any two sides of a triangle is less than the third side?
Question Description
Prove that the difference of any two sides of a triangle is less than the third side? for Class 9 2024 is part of Class 9 preparation. The Question and answers have been prepared according to the Class 9 exam syllabus. Information about Prove that the difference of any two sides of a triangle is less than the third side? covers all topics & solutions for Class 9 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Prove that the difference of any two sides of a triangle is less than the third side?.
Solutions for Prove that the difference of any two sides of a triangle is less than the third side? in English & in Hindi are available as part of our courses for Class 9. Download more important topics, notes, lectures and mock test series for Class 9 Exam by signing up for free.
Here you can find the meaning of Prove that the difference of any two sides of a triangle is less than the third side? defined & explained in the simplest way possible. Besides giving the explanation of Prove that the difference of any two sides of a triangle is less than the third side?, a detailed solution for Prove that the difference of any two sides of a triangle is less than the third side? has been provided alongside types of Prove that the difference of any two sides of a triangle is less than the third side? theory, EduRev gives you an ample number of questions to practice Prove that the difference of any two sides of a triangle is less than the third side? tests, examples and also practice Class 9 tests.
Explore Courses for Class 9 exam

Top Courses for Class 9

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev