Segment drawn on scale having end points O (0,0) and A 
is a line segment.
O A= ![\sqrt{[\frac{3}{4} -0]^{2} +[\frac{9}{10} -0]^{2}\\\\](https://tex.z-dn.net/?f=%5Csqrt%7B%5B%5Cfrac%7B3%7D%7B4%7D%20-0%5D%5E%7B2%7D%20%2B%5B%5Cfrac%7B9%7D%7B10%7D%20-0%5D%5E%7B2%7D%5C%5C%5C%5C)
O A = 
= 
= 
Now , the same segment actual structure having end points O'(0,0) and B (30,36) is also a line segment.
O'B= 
= 
= 
= 2√549
[Cancelling √549 from numerator and denominator]
So, Actual length = 40 × Length on scale
That one i believe would be A
Answer:
Then what is the radius of the circle? Since, the tangent of any point of a line is perpendicular to the radius through the point of contact. Hence, radius of the circle = 8 cm.
Plug in -3n as n into the functon K(n)=4n+5
so you get
K(-3n)=4(-3n)+5
K(-3n)=-12n+5
