The apothem of a polygon is a line made from the center to the midpoint of any side of the polygon. The radius, on the other hand, is the line from the center to any corner of the polygon. If you illustrate the problem, you can form a right triangle where the hypotenuse is the radius, and the other two legs are the apothem and half of one side of the polygon. 
Perimeter of octagon = 8*length of each side = 64
length of each side = 8 ft
Therefore,
Apothem = √(10.5^2 - (8/2)^2) = 9.71 ft
        
                    
             
        
        
        
Answer:
I dont speak English so I can't help anyone 
 
        
             
        
        
        
Answer:
what do you need help with?
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
1/3
Step-by-step explanation:
(-5,4)=(x1,y1)
(1,6)=(x2,y2)
Slope(m)=y2-y1
 _____
 x2-x1
 =6-4
 ____
 1+5
 =2÷6
 =1/3
 
        
             
        
        
        
1.  Replace f(x) with y:  y = 3x - 15
2.  Interchange x and y:  x = 3y - 15
3.  Solve this for y:  3y = x + 15, and y = (x + 15)/3
4.  Replace y with 
   -1                -1
 f   (x):           f   (x) = (x + 15) / 3            (answer)