Is y=8.75x linear or non linear and why

The table respent two linear functions the equation respented by the first tables is given

Ihave a triangle with a 60 degree angle. lets use d for that angle. what are the values of e and f if d is 60 degrees? and what do you notice about the values of e and f?

David leaves his house to go to school. he walks 200 meters west and 300 meters north. how far is david from his original starting point?