20. square-10+10=20x2=400m^2
circle- 3.14x10^2=3.14x100=314
400-314=86
86m^2
21.i don't get 21 sorry
        
             
        
        
        
Answer: 
 
Step-by-step explanation:
 The figure shows a right triangle.
 To calculate the measure of the angle A, you can use the inverse trigonometric function arctangent:
 
 Identify the angle  , the opposite side and the adjacent side:
, the opposite side and the adjacent side:
 
 Substitute into  .
. 
 The measure of the angle A is:
 
 Rounded to the nerarest hundreth:
 
 
        
             
        
        
        
Answer:
4/5
Step-by-step explanation:
I'm not exactly sure what this question is asking but I'm guessing it's asking to create a fraction with the numerator as 4 and denominator as 5.