If an exercise says "the measure of the smallest angle in a triangle is $20$", does that mean no other angle can have measure $20$? I have a question about this exercise:

If the measure of the smallest angle in a triangle is 20, then the measure of the greatest possible angle in this triangle is .....
  $$a ) 90$$
$$b )140$$
$$c ) 159$$
$$d ) 160$$

My question :

Does the word "smallest" mean that no other angle in the triangle is of measure 20, or is it okay to have another angle that size? Because, if there is no other one of measure 20, the answer is 90; but, if it's okay, the answer is 140.


What you're asking is a valid question: there is a difference between the minimal element and the least element.
In this question, I would assume that it's OK for the other angle to be 20. Because if not, then there is no measurement for the 2nd smallest angle. What would it be? 20.01? 20.0001? It's analogous to asking if there is a smallest positive real number.
