English

Abc is a Right Angled Triangle in Which ∠A = 90° and Ab = Ac. Find ∠B and ∠C.

Advertisements
Advertisements

Question

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

 

Advertisements

Solution

Given that ABC is a right angled triangle such that ∠A = 90° and AB = AC  Since,  

AB = AC ⇒ ΔABC is also isosceles 

∴ We can say that ΔABC is right angled isosceles triangle 

⇒ ∠C=∠B and ∠A=90°           ................(1) 

Now, we have
Sum of angled in a triangle =180°  

⇒ ∠A+∠B+∠C=180° 

⇒ 90°+∠B+∠B=180°            [∵ From (1)] 

⇒ 2∠B=180°-90° 

⇒`∠B=(90°)/2=45°`  

∴ ∠B=∠C=45°  

 

 

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 6 | Page 47

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

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.


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


Determine the measure of each of the equal angles of a right-angled isosceles triangle.


Two lines AB and CD intersect at O such that BC is equal and parallel to AD. Prove that the lines AB and CD bisect at O.


Prove that the medians of an equilateral triangle are equal. 


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


If the bisector of the exterior vertical angle of a triangle be parallel to the base. Show that the triangle is isosceles.  


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.  

 


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

If the altitude from one vertex of a triangle bisects the opposite side, then the triangle may be isosceles.  


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

In an equilateral triangle all angles are ..... 


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

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


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. 


In a triangle ABC, if AB =  AC and AB is produced to D such that BD =  BC, find ∠ACD: ∠ADC.


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


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


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


In the given figure, AB and CD are parallel lines and transversal EF intersects them at Pand Q respectively. If ∠APR = 25°, ∠RQC = 30° and ∠CQF = 65°, then


CDE is an equilateral triangle formed on a side CD of a square ABCD (Figure). Show that ∆ADE ≅ ∆BCE.


Show that in a quadrilateral ABCD, AB + BC + CD + DA < 2(BD + AC)


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×