which statement is expressed as a biconditional ?

1) two angles are congruent if they have the same measure
2) if two angles are both right angles , then they are congruent
3) two angles are congruent if and only if they have the same measure
4) if two angles are congruent , then they are both right angles

Question

which statement is expressed as a biconditional ?

1) two angles are congruent if they have the same measure
2) if two angles are both right angles , then they are congruent 
3) two angles are congruent if and only if they have the same measure 
4) if two angles are congruent , then they are both right angles

blurbendy · Answer

as a general rule of thumb, if the a sentence contains the phrase "if and only if", then that  is a pretty good indication that you're dealing with a biconditional