# Equilibrium for Coplanar Forces | Condition of Equilibrium Coplanar Forces

## Equilibrium for Coplanar Forces | Condition of Equilibrium Coplanar Forces:

Forces in **equilibrium** mean that they are **balanced**.

**Coplanar** forces act in the same plane. Two balanced forces are equal in **magnitude** but opposite in **direction** to the other.

We can see easily from the free body diagram that the resultant force is **zero**.

If we are considering **three** co planar forces in equilibrium, use the **triangle of forces rule**:

**If 3 forces acting at a point can be represented in size or direction by the sides of a closed triangle, then the forces are in equilibrium, provided their directions can form a closed triangle.**

This means that the forces can follow each other round a triangle

Notice how:

- The forces form into a closed triangle.
- The directions of the forces go round the triangle.

In **statics**, remember that all forces add up to zero. That does not mean that there are no forces; the forces balance each other out.

In statics problems, we need to know how to resolve forces, which can be done by:

- accurate drawing;
- use of trigonometry.