CBSE Class 9CBSE
Share
Notifications

View all notifications
Books Shortlist
Your shortlist is empty

Solution for In a δAbc, If Ab = Ac and ∠B = 70°, Find ∠A. - CBSE Class 9 - Mathematics

Login
Create free account


      Forgot password?

Question

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

Solution

Consider , ΔABC we have `∠B=70^@` and AB =AC 
Since, AB A C  ABC is an isosceles triangle
⇒ ∠B=∠C      [Angles opposite to equal sides are equal]

⇒`∠B = ∠C = 70^@` 

And also,
Sum of angles in a triangle `180^@` 

⇒ `∠A+∠B+∠C=180^@` 

⇒`∠A+70^@+70^@=180^@` 

⇒`∠A+140^@=180^@` 

⇒`∠A=180^@-140^@⇒∠A=40^@` 

  Is there an error in this question or solution?
Solution In a δAbc, If Ab = Ac and ∠B = 70°, Find ∠A. Concept: Congruence of Triangles.
S
View in app×