English

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

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

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

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Show that the angles of an equilateral triangle are 60° each.


In Fig. 10.40, it is given that RT = TS, ∠1 = 2∠2 and ∠4 = 2∠3. Prove that ΔRBT ≅ ΔSAT 

  


In an isosceles triangle, if the vertex angle is twice the sum of the base angles, calculate the angles of the triangle. 


PQR is a triangle in which PQ = PR and S is any point on the side PQ. Through S, a line is drawn parallel to QR and intersecting PR at T. Prove that PS = PT.  

 


In ΔABC, if ∠A = 40° and ∠B = 60°. Determine the longest and shortest sides of the triangle. 

 


Is it possible to draw a triangle with sides of length 2 cm, 3 cm and 7 cm? 

 


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. 


Fill in the blank to make the following statement true. 

Difference of any two sides of a triangle is........ than the third side. 

 


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, x + y =


In the given figure, if AB ⊥ BC. then x =


In the given figure, for which value of x is l1 || l2?


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


If the bisectors of the acute angles of a right triangle meet at O, then the angle at Obetween the two bisectors is


The side BC of ΔABC is produced to a point D. The bisector of ∠A meets side BC in L. If ∠ABC = 30° and ∠ACD = 115°, then ∠ALC = ______.


Which of the following correctly describes the given triangle?


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


Find all the angles of an equilateral triangle.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×