help with geometry

If a polygon has 3 sides, then it has to be a triangle. 

We can solve this problem by setting some variables. Let's set the smallest angle degrees as n. 

Now, since the angles from an arithmetic sequence, each angle is increasing an equal amount. 

This means if the first and last angle are 56 degrees apart, then the middle angle is \(56/2=23\) degrees bigger than n. 

Thus, we can write the equation \(n+(n+23)+(n+56)=180\)

Solving this equation, we get

\(3n+79=180\\ 3n=101\\ n=101/3\)

So our final answer is 101/3

This is not a whole number, but it does work. 

Thanks! :)

Let x be the smallest angle

Let  x + 2d   = the largest

(x + 2d)  - x  = 56

2d = 56

d =28

So

x + (x + d)  + (x + 2d)   =180

3x + 3d   =180

x + d  = 60

x + 28 = 60

x =60 - 28 =  32  = the smallest angle