"What is the sum of the measures of the interior angles formed by the boundary of this team pennant? A) 360 degrees B) 120 degrees C) 180 degrees D) 100 degrees?"

If the team pennant is triangular then the correct answer is C) 180 degrees

That is because the sum of all angles in a triangle is always 180. An easy example is a right triangle in which the right angle is 90, and the remaining two are 45.