Summary: By clicking on the grid above, you can create two vectors that are listed in the table. I suggest that you add the two vectors together using your calculator, and then click on the control buttons to check your answer step by step.
Details: When you first click on the screen a red vector is drawn from the origin to the point that you click. The magnitude and direction is placed in the table below the graph as vector 'A'. When you click again, vector a changes color to blue, and moves down to the vector 'B' slot. The new red vector is drawn from the origin to the place that you clicked.
Once you are satisfied with the two vectors and have tried working out their sum manually, you can click on the Comps of Vec 'A' button to find the components (with +x being toward the right). Similarly for the second vector.
The Sum Comps button forms the sum of the two x and y components and fills in their values in the spaces in the table.
The Mag & Dir button computes the magnitude and direction of the vector sum of 'A' + 'B'. This step also draws the resultant vector in black. It is possible to have the vector extend beyond the box. The numbers are accurate, and the black line shows the proper direction. It just means that the length of the resultant vector is too large to completely draw within the box.
Reset erases the table except for the two vectors.