Answer:
What is the angle between the positive horizontal axis and the line containing the points (9,7) and (10,10)?
I do not understand how to find the line from the two points, and then the angle
..
If you would plot these two points, you would notice a small right triangle is formed with the line connecting the points is the hypotenuse, a horizontal leg of =10-9=1, and a vertical leg of 10-7=3.
This gives the line a slope of 3/1=3 which is equal to the tangent of the angle which is equal to the angle you are trying to find.
Using a calculator,
arctan(3)=71.57 deg (ans)
Explanation: