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
 
        
             
        
        
        
So using the formula for the volume of a cone:
r^2pi x h/3
The height is always 4 times the radius, so:
h=4r 
Now putting the values into the original formula:
r^2pi x 4r/3
Now to see how much the radius increases per second:
r^2pi x 4r/3=300pi
r^2 x 4r/3=300
r^2 x 4r=900
r^2 x r=225
r^3=225
The radius increases by the cubic square root of 225 cm per second.
f(s)= 225^1/3 cm
        
             
        
        
        
If its less than 90, its a right triangle. Hope this helps!
        
             
        
        
        
Answer: 
3c=273 
c=91
2c= 212
C= 106
c= 91+ 106= 197
so they will need 197 canoes total
Why:
So first you have to determine a set variable to represent the number of canoes, I chose C. Then you make an equation to represent the number of canoes 273 people will use if they group into 3's, from this I got 3c=273. Solve for C and get 91.
The remainder of the group which is 485-273= 212 will use canoes in groups of 2's. To represent this, 2c=212. Solve for C and get 106. Combine 106 and 91 to get the total number of canoes. 
        
                    
             
        
        
        
-6, because you can see a pattern in which the x coordinate of each pair is reversed to the opposite value, from positive to negative.