Question

which of the following is an example of a biconditional statement?
if a polygon has three sides, then it is a triangle
if an angle is not 90 degrees then it is not a right angle
if a triangle is an isosceles triangle, then the triangle has two congruent sides
a polygon is a regular polygon if and only if all of its sides are congruent and all of its angles are congruent

Explanation:

A biconditional statement is of the form "p if and only if q", meaning both "if p then q" and "if q then p" are true. The first three options are one - way conditional statements. The last option "A polygon is a regular polygon if and only if all of its sides are congruent and all of its angles are congruent" is in the "if and only if" form.

Answer:

A polygon is a regular polygon if and only if all of its sides are congruent and all of its angles are congruent