Parallel lines - lines that will never cross over one another. They also share the same slope. (Remember slope?)
Transversal - a line that crosses over two or more lines at only one point each
The idea is that if a pair of parallel lines has a straight line that crosses them both, that line will create the same angle measurements in both parallel lines. But the angle measurements will only appear in similar positions in each parallel line. This is called corresponding angles (remember corresponding sides?)
From there, you can use alllll that you know about vertical angles, adjacent complementary, and adjacent supplementary angles to find all the measurements for these parallel lines when they're crossed by a transversal line.
Use the packet below to get extra practice to study for the quiz.
There are 2 main steps:
1) Make sure the vertex of the angle is lined up in the middle of the protractor's cross-hairs.
2) Line up the side of the angle with the bottom edge of the protractor's starting angle measurements (at 0 degrees).
If you see that the angle is obtuse, use the outside numbers,
If the angle is acute, use the inside numbers.
Video and guided notes were provided.
Exterior angles are outside of the given shape, while interior angles are inside the shape. If an angle is considered remote interior, it must be one of the furthest angles from the exterior angle.
These words interior and exterior will be used again when looking at the relationships between parallel lines.
The measurement of an angle can always be found by using the knowledge of triangle sum theorem and adjacent supplementary angles. The images below help to demonstrate this relationship.