Hello Priya,

Let us assume two forces F1 and F2.

In the question , there are two conditions given and accordingly we need to solve the equations by forming two equations.

In the first condition, the angle between two forces is 90 degree so apply the formula for the resultant which is =

F1^2 + F2^2 +2F1F2 *cos 90 = 10^2 - - - (i)

In the second condition the equation will come out to be :-

F1^2 + F2^2 + 2 F1F2 cos 60 = (√13)^2 - - - 2

So from the first get the value of F1 in terms of F2 and substitute in the second equation and a quadratic equation will be formed.