If a is at (−2,−8) and b is at (1,1), what are the coordinates of point c?

I don't have an answer for you, but I do have an important hint ... one that will
stand you in good stead as you go further in your mathematical studies:

The reason there's a drawing right next to this question in the book or on the
homework sheet is that the question can't be answered without the drawing.

Answerdistinguish between the mercalli scale and the richter scale;