Hello Aspirant,

As we know that Force is the vector quantity and hence it's resultant would be given as per the formula mentioned below :-

R = √{A² + B² + 2A.Bcos}

Here is angle between two forces which we need to find out, so using the formula we will solve the question.

According to the question both the forces have magnitude F and resultant F, so

F = √{F² + F² + 2.F.Fcos}

⇒F² = F² + F² + 2F².cos

⇒- F² = 2F²cos

⇒ -1/2 = cos

⇒cos = -1/2 = cos120°

⇒ = 120°

Which means that if both the forces have same magnitude and same resultant then angle between them will be 120°.

I hope this information helps you.

Good Luck!!