The three angles of a triangle add up to 180 degrees.  The largest angle is 5 times bigger than the smallest. The middle angle is 3 times bigger than the smallest. How many degrees is the smallest angle?
Define a variable ** Let x be the smallest angle.
Write an equation ** The combination of the three is x + 3x + 5x = 9x.
Simplify ** Thus 9x = 180.
Divide by 9 ** So x = <<20=20>>20.
#### 20