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Answer:</h2>
Option: C is the correct answer.
C. Two figures are congruent if and only if their areas are equal.
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Step-by-step explanation:</h2>
A)
Two line segments are congruent if and only if they are of same length.
This option is correct because for two line segments to be congruent they must have same length.
B)
An angle is straight if and only if its measure is 180.
This option is correct.
Because the angle along a straight line always measure 180 degree and vice-versa.
C)
Two figures are congruent if and only if their areas are equal.
This options is incorrect.
Since, a triangle and a square may have same area but they are not congruent.
Since, two figures are congruent if they have same shape as well as size.
D)
A whole number is odd if and only if the number is not divisible by 2.
This option is correct.
Since, a odd number is a number which is not divisible by 2 .
and an even number is a number which is divisible by 2.