You have to set up a ratio and solve
        
             
        
        
        
First the radius is half of 70 
35
then you use C=2piR
C=2x3.14x35
C= 219.8
hope this helps
        
             
        
        
        
Answer:   (A) -5   and   (C) -3
<u>Step-by-step explanation:</u>
See attached graph.  They intersect when x = -5 and when x = 3
 
        
             
        
        
        
Area = (theta/360)* pi * r^2 
where theta is the angle of  the sector 
subs by your givens in the above equation 
2.512 = (theta/360) * pi * (4)^2 
theta = (2.512 * 360) /(pi*(4)^2)
theta = 18 degree 
        
             
        
        
        
Answer:
10 feets 
Step-by-step explanation:
Given that:
Road sign shadow (Rs) = 4 feets
Height of man (Hm) = 6
Man shadow (Ms) = 2.4 feets
Height of road sign (Hr) = x
Height of road sign / shadow of road sign = height of man / shadow of man
Hr/Rs = Hm / Ms
x / 4 = 6 / 2.4
Cross multiply :
4*6 = 2.4*x
24 = 2.4x
x = 24 / 2.4
x = 10 feets
Hence, height of road sign = 10 feets