If in a ` A B C ,cos^2A+cos^2B+cos^2C=1,` prove that the triangle is right angled.

If in a ABC,cos^(2)A+cos^(2)B+cos^(2)C=1 prove that the triangle is right angled.

In triangle ABC, cos^2A + cos^2B - cos^2C = 1, then the triangle is necessarily

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 a triangle A B C , if cos A+2\ cos B+cos C=2. prove that the sides of the triangle are in A.P.

For a A B C , it is given that cos A+cos B+cos C=3/2 . Prove that the triangle is equilateral.

If in a triangle ABC,(2cos A)/(a)+(cos B)/(b)+(2cos C)/(b)=(a)/(bc)+(b)/(ca), then prove that the triangle is right angled.

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 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 right angled Delta BC,cos^(2)A+cos^(2)B cos^(2)C=