Question

18.

Which of the following statements is true?
A. Angles are supplementary if and only
if they form a linear pair.
B. It is Valentine's Day if and only if it is
February.
C. A number is even if and only if it is
divisible by 2.
D. Lines are skew if and only if they are
non-coplanar.

Answer 1

Answer: The correct answer is D, Lines are skew if and only if they are non-coplanar.

In geometry, lines are said to be skew if they are non-coplanar, meaning they do not lie in the same plane. They also do not intersect.

Option A is incorrect because angles can be supplementary (add up to 180 degrees) even if they do not form a linear pair (meaning they do not share a common vertex and a common side).

Option B is incorrect because Valentine's Day does not always fall in February. It is February 14th, but it could fall on a different month in a different year.

Option C is correct because a number is even if and only if it is divisible by 2. An even number can be divided evenly by 2, while an odd number cannot.