SOLUTION: Determine the truth value of these statements: If a Vertex angle isn't an obtuse angle, then the isosceles triangle is not obtuse. If an isosceles triangle isn't obtuse, then

Algebra ->  Geometry-proofs -> SOLUTION: Determine the truth value of these statements: If a Vertex angle isn't an obtuse angle, then the isosceles triangle is not obtuse. If an isosceles triangle isn't obtuse, then      Log On


   

Question 1156542: Determine the truth value of these statements:
If a Vertex angle isn't an obtuse angle, then the isosceles triangle is not obtuse.
If an isosceles triangle isn't obtuse, then the vertex angle is not obtuse.
I've written true for both of these, but I'm skeptical about the answer I got...
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


A triangle can't have two obtuse angles.

Therefore, since in an isosceles triangle the base angles are congruent, an isosceles triangle is obtuse IF AND ONLY IF the vertex angle is obtuse.

That makes both of the statements true.