English

Angles A, B, C of a Triangle Abc Are Equal to Each Other. Prove that δAbc is Equilateral. - Mathematics

Advertisements
Advertisements

Question

Angles A, B, C of a triangle ABC are equal to each other. Prove that ΔABC is equilateral. 

Advertisements

Solution

Given that angles A,B,C of a triangle ABC equal to each other.
We have to prove that ΔABC is equilateral We have, ∠A = ∠B =∠C
Now, 

[Opposite sides to equal angles are equal] 

and ∠B = ∠C ⇒ AC = AB 

From the above we get 

AB= BC =AC  

⇒ ΔABC is equilateral 

shaalaa.com
  Is there an error in this question or solution?
Chapter 12: Congruent Triangles - Exercise 12.3 [Page 47]

APPEARS IN

RD Sharma Mathematics [English] Class 9
Chapter 12 Congruent Triangles
Exercise 12.3 | Q 5 | Page 47

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

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

  1. ΔABE ≅ ΔACF
  2. AB = AC, i.e., ABC is an isosceles triangle.


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

 


The vertical angle of an isosceles triangle is 100°. Find its base angles. 


Which of the following statements are true (T) and which are false (F): 

Angles opposite to equal sides of a triangle are equal 


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

If altitudes CE and BF of a triangle ABC are equal, then AB = .... 


Prove that the perimeter of a triangle is greater than the sum of its altitudes. 


Which of the following statements are true (T) and which are false (F)? 

Sum of any two sides of a triangle is greater than twice the median drawn to the third side. 


Which of the following statements are true (T) and which are false (F)? 

If two angles of a triangle are unequal, then the greater angle has the larger side opposite to it. 


Which of the following statements are true (T) and which are false (F)?  

Of all the line segments that can be drawn from a point to a line not containing it, the perpendicular line segment is the shortest one. 


Write the sum of the angles of an obtuse triangle.


If the angles of a triangle are in the ratio 2 : 1 : 3, then find the measure of smallest angle.


In a ΔABC, if ∠A = 60°, ∠B = 80° and the bisectors of ∠B and ∠C meet at O, then ∠BOC =


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


In the given figure, if BP || CQ and AC = BC, then the measure of x is


The angles of a right angled triangle are


Which of the following correctly describes the given triangle?


In triangles ABC and PQR, AB = AC, ∠C = ∠P and ∠B = ∠Q. The two triangles are ______.


In ∆PQR, ∠P = 70° and ∠R = 30°. Which side of this triangle is the longest? 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×