Question: If a ray divides an angle into two supplementary angles, then the original angle is a straight angle.

True?

5 answers

Yes.
If a ray divides an angle into two supplementary angles, then the original angle is a straight angle.
true
If a ray divides an angle into two complementary angles, then the original angle is a right angle.

I know it's true but how do i explain it to my teacher.
You say that you know it is a right angle because a complementary angle is 90 degrees and a right angle is also 90 degrees so that is the answer