Answer:
4
Step-by-step explanation:
 
        
                    
             
        
        
        
I believe the answer is 4 if you need an explanation then reply to me!
        
                    
             
        
        
        
Answer:
105 degrees
Step-by-step explanation:
Recall that the sum of angles in a triangle is 180 degrees. As such, where a, b and c are the angles of a triangle then
a + b + c = 180 ( all in degrees) 
Given that two angles of a triangle measure 55 and 20, let the size of gthe 3rd be T then
55 + 20 + T = 180
simplify
75 + T = 180
Subtract 75 from both sides
T = 180 - 75
T = 105
 
        
             
        
        
        
Answer:
look at the picture i have sent
 
        
             
        
        
        
8.9
The equation for the grain size is expressed as the equality:
Nm(M/100)^2 = 2^(n-1)
where
Nm = number of grains per square inch at magnification M.
M = Magnification
n = ASTM grain size number
Let's solve for n, then substitute the known values and calculate.
Nm(M/100)^2 = 2^(n-1)
log(Nm(M/100)^2) = log(2^(n-1))
log(Nm) + 2*log(M/100) = (n-1) * log(2)
(log(Nm) + 2*log(M/100))/log(2) = n-1
(log(Nm) + 2*log(M/100))/log(2) + 1 = n
(log(33) + 2*log(270/100))/log(2) + 1 = n
(1.51851394 + 2*0.431363764)/0.301029996 + 1 = n
(1.51851394 + 0.862727528)/0.301029996 + 1 = n
2.381241468/0.301029996 + 1 = n
7.910312934 + 1 = n
8.910312934 = n
So the ASTM grain size number is 8.9
If you want to calculate the number of grains per square inch, you'd use the 
same formula with M equal to 1. So:
Nm(M/100)^2 = 2^(n-1)
Nm(1/100)^2 = 2^(8.9-1)
Nm(1/10000) = 2^7.9
Nm(1/10000) = 238.8564458
Nm = 2388564.458
Or about 2,400,000 grains per square inch.