Lines room parallel if they are always the very same distance personal (called "equidistant"), and will never ever meet. Just remember:
Always the very same distance apart and also never touching.
You are watching: Do parallel lines have to be the same length
The red heat is parallel come the blue heat in each of this examples:
Try that yourself:
Pairs of Angles
When parallel lines get crossed by one more line (which is called a Transversal), you have the right to see that countless angles are the same, together in this example:
These angles deserve to be made right into pairs the angles which have special names.
Click top top each surname to check out it highlighted:
Now play v it here. Shot dragging the points, and choosing various angle types. Girlfriend can likewise turn "Parallel" turn off or on:
Testing because that Parallel LinesSome of those one-of-a-kind pairs of angles have the right to be used to check if currently really space parallel:
|These currently are parallel, since a pair of equivalent Angles space equal.|
|These lines space not parallel, because a pair that Consecutive internal Angles perform not add up to 180° (81° + 101° =182°)|
|These currently are parallel, because a pair of alternate Interior Angles space equal|
angles On a directly Line Angles roughly a suggest Transversal Congruent angles Vertical angle Geometry index