Math 5 ! a classmate believes that a triangle can have both right angle and an obtuse angle. which of the following statements would you use to convince him that he is incorrect. a. its is not possible because the sum of the angles in the triangle can't exceed 180 d. b. it is not possible because if a triangle has an obtuse triangle , that means all the angles are obtuse angles. c. it is not possible because if a triangle has a right triangle, that means all the angles are right angles. its is possible. the classmate is correct.