English

In ΔABC, AD is the perpendicular bisector of BC (see the given figure). Show that ΔABC is an isosceles triangle in which AB = AC.

Advertisements
Advertisements

Question

In ΔABC, AD is the perpendicular bisector of BC (see the given figure). Show that ΔABC is an isosceles triangle in which AB = AC.

Sum
Advertisements

Solution

Since AD is the bisector of BC.

∴ BD = CD

Now, in △ABD and △ACD, we have

AD = DA           ...[Common]

∠ADB = ∠ADC     ...[Each 90°]

BD = CD             ...[Proved above]

∴ △ABD ≌ △ACD       ...[By SAS congruence]

⇒ AB = AC         ...[By Corresponding parts of congruent triangles]

Thus, △ABC is an isosceles triangle.

shaalaa.com
  Is there an error in this question or solution?
Chapter 7: Triangles - EXERCISE 7.2 [Page 97]

APPEARS IN

NCERT Mathematics [English] Class 9
Chapter 7 Triangles
EXERCISE 7.2 | Q 2. | Page 97

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

ABC is an isosceles triangle in which altitudes BE and CF are drawn to equal sides AC and AB respectively (see the given figure). Show that these altitudes are equal.


ΔABC is an isosceles triangle in which AB = AC. Side BA is produced to D such that AD = AB (see the given figure). Show that ∠BCD is a right angle.


In a ΔABC, if ∠A=l20° and AB = AC. Find ∠B and ∠C. 

 


AB is a line seg P and Q are points on opposite sides of AB such that each of them is equidistant from the points A and B (See Fig. 10.26). Show that the line PQ is perpendicular bisector of AB. 

 


In a ΔABC, if AB = AC and ∠B = 70°, find ∠A. 


If the base of an isosceles triangle is produced on both sides, prove that the exterior angles so formed are equal to each other. 


ABC is a right angled triangle in which ∠A = 90° and AB = AC. Find ∠B and ∠C. 

 


ABC is a triangle in which BE and CF are, respectively, the perpendiculars to the sides AC and AB. If BE = CF, prove that ΔABC is isosceles  


Fill the blank in the following so that the following statement is true. 

In a ΔABC if ∠A = ∠C , then AB = ...... 


Fill the blank in the following so that the following statement is true. 

In an isosceles triangle ABC with AB = AC, if BD and CE are its altitudes, then BD is …… CE.


Fill in the blank to make the following statement true. 

The sum of three altitudes of a triangle is ..... than its perimeter. 


In the given figure, what is y in terms of x?


The angles of a right angled triangle are


Which of the following correctly describes the given triangle?


In ∆ABC, AB = AC and ∠B = 50°. Then ∠C is equal to ______.


In ∆PQR, if ∠R > ∠Q, then ______.


AD is a median of the triangle ABC. Is it true that AB + BC + CA > 2AD? Give reason for your answer.


Is it possible to construct a triangle with lengths of its sides as 8 cm, 7 cm and 4 cm? Give reason for your answer.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×