T = How tall they are. 
Robin = 180
His brother = x cm shorter
T = 180 - x
        
             
        
        
        
35 x .6 = 21 so there must be 21 people present to take a vote.
        
             
        
        
        
I believe that the answer would be C. because each triangle that is “broken up” in the hexagon is equilateral meaning that angle 1 and angle 3 would be congruent and equal to 60, and since angle 2 is half the measure of angle 1 it would be 30. Hope this helps!
        
                    
             
        
        
        
Y=2 1/2x+5. Or if it’s wrong the 2 1/2 is negative.
        
             
        
        
        
(((1/y - 1) + (5/12)) = (-2/3y - 3))
((((1)(12)/12(y - 1) + (5(y + 1)/12(y + 1) = (-2/3y - 3))
((12/12y - 12) + (5y + 5/12y - 12)) = (-2/3y - 3))
((5y + 17/12y - 12) = (-2/3y - 3)
(12y - 12/5 + 17) × (5y + 17/12y - 12) = (-2/3y - 3)(12y - 2/5 + 17)
y = -21y + 4/66y - 66
y = -7/22 - 2/33
y = -25/66