If ` A B C ,sinC+cosC+sin(2B+C)-cos(2B+C)=2sqrt(2.)` Prove that ` A B C` is right-angled isosceles.

If cos B=(sin A)/(2sin C) then prove that the triangle is isosceles.

In a Delta ABC if (a+b)cos((B)/(2))=b(a+c)cos((C)/(2)) then prove that the triangle ABC is isosceles.

In triangle ABC if 2sin^(2)C=2+cos2A+cos2B , then prove that triangle is right angled.

If in a Delta ABC, c(a+b) cos B//2 = b(a+c) cos C//2 , prove that the triangle is isosceles.

In any triangle ABC, if (cos A + 2 cos C)/(cos A + 2 cos B) = (sin B)/(sin C) then prove that, the triangle is either isosceles or right angled.

In Delta ABC, if sin A+sin B+sin B+sin C=1+sqrt(2) and cos A+cos B+cos C=sqrt(2) then the triangle is

If : cos^(2) A + cos^(2) B + cos^(2) C = 1, "then" : Delta ABC is A)scalane B)equilateral C)isosceles D)right angled

If A+B+C= pi and cos A=cos B. cosC,prove that cot B cot C= 1/2

In any triangle ABC if 2cos B=(a)/(c), then the triangle is(A) Right angled (C) Isosceles (B) Equilateral (D) None of these

In a triangle ABC, if sin A sin(B-C)=sinC sin(A-B) , then prove that cos 2A,cos2B and cos 2C are in AP.