You left something out of your given. The hypothesis of the theorem contains the word "altitude". An altitude is not just any old line from one vertex to a point on the opposite side. What does the fact that AC is an altitude say about the relationship between AC and BD?
A hint for the proof: Another way of saying "AC bisects the angle BAD" is "angle BAC = angle CAD".
By the way, the kinds of questions you are asking are things you should be able to ask your teacher, I think.
TiGER wrote: > > I have a statement and have to write down what the Given is, what To > Prove, Anaylsis, and Draw a figure, and the two-column proof. Not sure > how to draw the figure as accurate as possible though. Anyway, here is > the problem: > > Theorem: In an isosceles triangle, an altitude drawn to the base of > the triangle bisects the vertex angle of the triangle. > > I drew an isosceles triangle with a line straight down the middle. I > labeled the points A-D going from left to right and top to bottom. > This is what I get out of the statement: > > Given: Triangle ABD is an isosceles triangle > To Prove: Segment AC bisects Angle BAD > > I doubt that is right but that's what I get from the statement.