How is this done and what would be the answer? truss forces for engineering

In two or more complete sentences, determine the appropriate model for the given data and explain how you made your decision. (1,-1), (2,0.5), (5,1.5), (8,2)

How can you find the magnitude of a vector, v = < x, y > , where the horizontal change is x and the vertical change is y?

Tim tradesman pays $2,000 annually for $125,000 worth of life insurance. what is the cash value of the policy after 10 years? 11,125 13,125 17,800 111,250