In a `triangle ABC` `angle A=pi/2` then `cos^2B+cos^2C=`

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

If A, B, C are the angles of a right angled triangle, then (cos^2A+ cos^2B+ cos^2C) equals

Statement-1: In a triangle ABC, if sin^(2)A + sin^(2)B + sin^(2)C = 2 , then one of the angles must be 90 °. Statement-2: In any triangle ABC cos 2A + cos 2B + cos 2C = -1 - 4 cos A cos B cos C

In triangle ABC, /_C = (2pi)/3 then the value of cos^2 A + cos^2 B - cos A.cos B is equal

If Delta ABC is right triangle and if angleA = (pi)/(2) , then prove that cos^(2)B + cos^(2)C = 1

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

If Delta ABC is right triangle and if angleA = (pi)/(2) , then prove that cos B - cos C = -1 + 2 sqrt(2) cos"" (B)/(2) sin"" (C )/(2) .

In triangle ABC,/_C=(2 pi)/(3) then the value of cos^(2)A+cos^(2)B-cos A*cos B is equal