In the diagram of a toy trailer below, when a child pulls on the handle, some of the 5 newton (N) force pulls the trailer upwards away from the ground and some of the force pulls it to the right.
Vector diagrams can be used to resolve the pulling force into a horizontal component acting to the right and a vertical component acting upwards.
Draw a right-angled triangle to scale, in which each side represents a force. Try to choose a simple scale, for example 1 cm = 1 N. For the toy trailer example above, draw:
Measure the lengths of the horizontal and vertical lines. Use the scale for the first line to convert these lengths to the corresponding forces.
When combined, the two component forces have the same effect as the single force. In this example, the child's pulling force.