If P=360, then 360yd / 4 sides = 90yds each side. Now that it is a rectangle, the Length should be more than the width, so if the length is 20yds more than the width, do 90 - 20 two times,  Width= [ (90yds - 20yds)*2 ] 
To sum things up, Length = 110; Width = 70. | 110*2 = 220, 70 * 2 = 140, 220+140 = 360.
        
                    
             
        
        
        
Step-by-step explanation:
V= 32.5ℓ (m^3) 
when ℓ= 8.4 m , V= 273 m^2 
 
 
        
             
        
        
        
It will be 8 years old when it is worth $4800.
        
             
        
        
        
a=adult tickets
s = senior tickets
a+s=465       a = 465-s
23a + 13s = 7145
substitute in a = 465-a
23 (465-s) + 13s = 7145
distrubute
10695 - 23s +13s =7145
combine like terms
10695 - 10s = 7145
subtract 10695 from each side
-10s = -3550
divide by -10
s = 355
senior tickets sold 355