Parallel Lines: Identifying and defining elements

In drawing B, we observe two right angles, which teaches us that they are practically equal. From this, we can conclude that they are corresponding angles, located at the intersection of two parallel lines.

In drawing A, we only see one right angle, so we cannot deduce that the two lines are parallel.

Let's 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.

Let's remember that perpendicular lines are lines that form a right angle of 90 degrees between them.

The only drawing where it can be seen that the lines form a right angle of 90 degrees between them is drawing A.

Perpendicular lines are lines that form a right angle of 90 degrees between them.

The only drawing where the lines form a right angle of 90 degrees between them is drawing A.

Lines that intersect each other are lines that divide the side into two equal parts.

The drawings showing that the lines divide the sides into equal parts are drawings 1+3.

In drawing 2, the lines are perpendicular and vertical to each other, and in drawing 4, the lines are parallel to each other.

Parallel lines are lines that, if extended, will never meet.

In the drawings A+B+D if we extend the lines we will see that at a certain point they come together.

In drawing C, the lines will never meet, therefore they are parallel lines.

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

We can see that what all lines have in common is that they form a right angle of 90 degrees with each other.

Let's remember that lines that form a right angle of 90 degrees with each other are perpendicular and vertical lines.

Therefore, the correct answer is a.

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

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

We'll remember that lines that cross each other are lines that will meet at a certain point.

Therefore, the correct answer is a.

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

We can see that what all these lines have in common is that they form a right angle of 90 degrees with each other.

Let's remember that lines that form a right angle of 90 degrees with each other are perpendicular and vertical lines.

Therefore, the correct answer is a.

Remember the properties of parallel lines.

Since there is no connection between the size of the line and parallelism, the lines are indeed parallel.

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.

For the lines to be parallel, the two angles must be equal (according to the definition of corresponding angles).

Let's compare the angles:

$2x+10=70-x$

$2x+x=70-10$

$3x=60$

$x=20$

Once we have worked out the variable, we substitute it into both expressions to work out how much each angle is worth.

First, substitute it into the first angle:

$2x+10=2\times20+10$

$40+10=50$

Then into the other one:

$70-20=50$

We find that the angles are equal and, therefore, the lines are parallel.