Thread: Transitive & Substitution Properties

I have a problem that I need to EXPLAIN. I need help explaining this problem.


Line AB and Line CD intersect at E, and the ratio of Angle AED is 2:3.
Write an argument to show that it is impossible for Angle DEB to be 80.

Imagine two rays that cross each other. The intersection point in the middle is E. The point in the upper left corner is A, the point in the upper right corner is D, the point in the lower left corner is C and the point in the lower right corner is B.

I assume by angular ratio: $\displaystyle \frac{{m\left( {\angle AED} \right)}}{{m\left( {\angle DEB} \right)}} = \frac{2}{3}$.

If that is correct, is it possible for $\displaystyle \left( {\angle DEB} \right) = 80$???

I'm very sorry... for the problem, I meant to say;


Line AB and Line CD intersect at E, and the ratio of Angle AEC to Angle AED is 2:3. Write an ARGUMENT to show that it is IMPOSSIBLE for Angle DEB to be 80.


I'm very sorry about that.