Answer:
63.59 in²
Step-by-step explanation:
The formula to find the area of a square: a², where a is the side.
The formula to find the area of a circle: πr², where r is the radius (diameter ÷ 2), and the pi is alterable (3.14 or 3.142 or 22/7).
1) Find the diameter of the circle. The side of a square is the diameter.
a²
a = √81
a = 9
2) Plug the values into the formula of the area of a circle. 9 ÷ 2 = 4.5 (radius).
= 3.14 x 4.5²
= 3.14 x 20.25
= 63.585
3) Round off the result to the nearest hundredth. 
= 63.59
 
        
             
        
        
        
I assume that the numbers are supposed to be written as 7.14 x 10^10 for December and 3.21 x 10^10. The total mail delivered is the sum of these two numbers.
                         (7.14 x 10^10) + (3.21 x 10^10) = 1.035 x 10^11
        
                    
             
        
        
        
Answer:
20 + 2 units
Step-by-step explanation:
because the perimeter of ∆ ABC is the answer 20 + 2
 
        
             
        
        
        
Factor and set each factor equal to zero:
x = -3, 3, 2i, -2i
        
             
        
        
        
Answer:
38
Step-by-step explanation:
j/-2=-19
j=38