Statics problem equilibrium of a particle 2D

[red1312]

1. Homework Statement
In the picture

Homework Equations

In the picture

The Attempt at a Solution

In the picture My question is .. Why in Fx has sin and Fy has cos ?

 

[SteamKing]

1. Homework Statement
In the picture

Homework Equations

In the picture

The Attempt at a Solution

In the pictureMy question is .. Why in Fx has sin and Fy has cos ?

Because of the way the angles are defined and because of how you would find the components of the forces shown. Remember how sine and cosine are defined on a triangle: