Biconditional statements: are both correct? is one better?

[redhead]

We are currently covering logic statements, converses, inverses, etc. I understand WHAT a biconditional statement is, but I'm wondering if it can be written either way.
Such as:
Definition: If 2 lines intersect to form a right angle, then they are perpendicular.
Converse: If 2 lines are perpendicular, then they intersect to form a right angle.
Biconditional statements:
#1 Two lines are perpendicular if and only if they intersect to form a right angle.
#2 Two lines intersect to form a right angle if and only if the two lines are perpendicular.

Are both biconditional statements above correct? Is one preferred over the other?

 

[mmm4444bot]

Re: Biconditional statements

#1 Two lines are perpendicular if and only if they intersect to form a right angle.
#2 Two lines intersect to form a right angle if and only if the two lines are perpendicular.

Are both biconditional statements above correct? Is one preferred over the other?

I believe that either biconditional statement can be used without preference.

This is because I believe that EACH biconditional statement expresses BOTH the definition AND its converse.

In other words, if you give me only #1, then I can deduce both the definition and the converse of the definition from it.

Likewise, if you give me only #2, then I can deduce the same.

"He will be president if and only if he wins the election".

This biconditional statement tells me a definition and its converse:

He will be president if he wins the election.

If he wins the election, then he will be president.

However, the Supreme Court may rule against me, so, just in case there's a pedantic consideration, I would run this question by your instructor as well!

Cheers,

~ Mark