There are 15,500 sheets of paper
        
             
        
        
        
We know, sum of all the angles in a triangle is equal to 180 degree
So, 90 + 2x + 3x = 180
5x = 180-90
x = 90/5
x = 18
∠ANB = 2x = 2(18) = 36
∠BNC = 3x = 3(18) = 54
Hope this helps!
        
             
        
        
        
Step-by-step explanation:
L.H.S=(1-cosB)(1+cosB)
 =(1-cos^2B). {using (a+b) (a-b)=(a^2-b^2)in second step} 
 =sin^2B
 =1/cosec^2B
Therefore,L.H.S=R.H.S proved
 
        
             
        
        
        
Answer:
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Step-by-step explanation:
please send me only