Answer:
y = 15x + 65
Step-by-step explanation:
To find the equation, we can use two points in the graph to find the parameters 'a' and 'b' in the equation:
y = ax + b
For the value x = 1, we have y = 80
For the value x = 9, we have y = 200
So we have that:
80 = a*1 + b
200 = a*9 + b
Making the second equation minus the first one, we have:
8a = 120
a = 15
Now we can find 'b':
80 = 15 + b
b = 65
So the equation is y = 15x + 65
S=180(n-2)
Where S is the sum of the interior angles and n is the number of sides.
So If you knew the sum and wanted to know the number of sides you'd rearrange accordingly...
n=S/180+2 or more neatly
n=(S+360)/180