Theorems and Statements (With pic of problem)

[javytheman]

(Here is the problem)

(Pic of the only thing that i could find that i thought would help me.)



How would i solve this? At First i thought it was bi-conditional but I look again and see that im completely wrong.
Does anyone know how to solve this? I'm hung up on this problem...

edit: I have no clue what the second one is either.

 

[Ishuda]

...How would i solve this? At First i thought it was bi-conditional but I look again and see that im completely wrong.
Does anyone know how to solve this? I'm hung up on this problem...

edit: I have no clue what the second one is either.

Replacing the image:

Theorem 8.18: If a quadrilateral is a kite, then its diagonals are perpendicular.

Diagonal AC is horizontal and BD is vertical, so AC is perpendicular to DB, but ABCD is not a kite. Using this information, explain why Theorem 8.18 is not written as biconditional.

Theorem 8.18 is a __________ statement. The information shows the __________ of Theorem 8.18 is false by counterexample. Thus Theorem 8.18 can not be written as a biconditional.

What does biconditional mean? How is that different than a conditinoal statement? What is it when you turn the statement around? What if both the statement and its converse are true?