Answer:
Step-by-step explanation:
Find a point on the line ....say 9, 3
that is a horizontal distance of 9 and a vertical distance of 3
these distances are the legs of a RIGHT triangle
for RIGHT triangles Tan Θ = opposite leg/ adjacent leg
so tan Θ = 3/9
then Θ = arctan (3/9) = 18 degrees (rounded)