Perpendicular Lines

Remember that parallel lines are lines that, if extended, will never intersect.

In diagrams a'+b'+c', all the lines intersect with each other at a certain point, except for diagram d'.

The lines drawn in answer d' will never intersect.

Take note that perpendicular lines are lines that intersect at a 90-degree angle.

In order to better examine the types of angles that the lines create with one another, let's draw a T at the intersection point of the lines as follows:

Notice that from the drawings, in answers 1+2 a right angle is formed, meaning the lines in these drawings are perpendicular.

Let's remember the different properties of lines.

The lines are not parallel since they intersect.

The lines are not perpendicular since they do not form a right angle of 90 degrees between them.

Therefore, no answer is correct.

Let's first think about the different definitions of various lines.

We can see that what is common to all of the lines is that they intersect each other, meaning they have a point of intersection.

Remember that lines that cross each other are lines that will meet at a certain point.

Therefore, the correct answer is (a).

Upon observation we can see that all the lines form a right angle of 90 degrees with each other.

Typically lines that form a right angle of 90 degrees with each other are perpendicular and vertical lines.

Therefore, the correct answer is a.