If in a triangle ABC,

c(a+b) Cos B/2 =b(c+a) Cos C/2
then the triangle is :-
1. isosceles
2. Right angled
3. isosceles or right angled
4. none of these

I want the explanation

3 answers

1. Isosceles
Put B=C
AFTER PUTTING AND SIMPLIFYING WE ARE GETTING AB=AC THEN TWO SIDES ARE EQUAL THEN IT IS A ISOSCELES TRIANGLE