Answer:
Step-by-step explanation:
We know that "bending" means to force or shape something into a curve or certain angle.
Now, when we bend something we are actually using a pair of forces, not just one, because you can't bend using only one forces, that would imply using one hand which is impossible. Notice that you need to forces to be applied at different points in the same direction to create the curve, these forces must be applied a certain distance away from the equilibrium point which is between the points of application.
Therefore, there are two forces involves because we need to use two points of application to bend something.