Hello
<span>an equation for the line in point-slope form and general form is :
y = ax+b   a : </span>slope  ; the <span>Passing through (x' ; y')
</span>y' = ax'+b 
y-y' =a(x-x')      and : x' =2   y' = - 1
calculate a :
let :  y = ax+b .....(D)
   ....<span>3y-x=7</span>....(D') or  y = (1/3)x+7/3
.(D) perpendicular to(D') : slope (D) × slope (D') = -1 
 slope (D') = 1/3
slop(D)×(1/3) = -1
slope (D) = -3
equation for the line    :   y-y' =a(x-x') 
y+1 =(-3) (x-2)
        
             
        
        
        
Answer:
The actual length of 60 cm is modeled as 1 cm length.
Step-by-step explanation:
The diameter of the sweep of the main rotor of the helicopter is 18.6 meters i.e. 1860 cm.
Now, the toy model of the helicopter has a sweep of 31 cm.
Therefore, the scale in which the model is made is 1860 : 31 i.e. 60 : 1 ratio.
So, the actual length of 60 cm is modeled as 1 cm length. (Answer) 
 
        
                    
             
        
        
        
What do you want exactly i don’t understand the question. Comment and ill solve it