For what angle between A and B,|A+B|=|A-B|?

Resultant of vectors A and B can be expressed as A+B which is equalA2+B2+2ABcos(θ)Subtraction of vectors A and B can be expressed as A-B which is equalA2+B2-2ABcos(θ)It can be written as:A2+B2+2ABcos(θ)=A2+B2-2ABcos(θ)A2+B2+2ABcos(θ)=A2+B2-2ABcos(θ)cos(θ)=-cos(θ)Hence the value is  θ=90°