#### When two lines intersect they create four angles. The adjacent angles are supplementary angles and the angles directly opposite one another are vertical angles. A little math for you the sum of supplementary angles is 180 degrees and vertical angles have equal values. Using this little tidbit of information we can completely understand all the measures of the angles in intersecting lines, if we know just one measure of an angle.

How do you calculate the measures of angles formed from two intersecting lines?
Angles are measured in degrees. They are measured with the help of a protractor. An angle is the quantity of turn between two intersecting straight lines or lines which have a common endpoint that is known as the vertex of the angle.
Before measuring angles, it is necessary to label them to avoid confusion and be clear about which angle you are talking about.
There are different ways to indicate an angle. You can indicate an angle with ^ placed above the name of the point where the it is formed. Another way is to draw ∠ in front of the point's name. You can also utilize the names of the intersecting lines that form it.
To measure the angle, ensure that the origin (center) of the protractor is placed exactly on the vertex of it that you need to measure. The origin is located on the baseline of the protractor. When measuring it, ensure that one side of the baseline of the protractor is placed exactly on one of the intersecting lines that make the arm of the angle being measured.
A protractor has two zeros. If you start measuring using the zero on the left side of the protractor, you should use the outer scale of the protractor. Alternatively, if you start measuring from the zero on the right side, use the inner scale. Now, read the number that is aligned with the other arm of the angle, and that's how you get the reading.
These worksheets explain how to calculate the angle between two intersecting lines. Students will be supplied with at least one known measure, and must determine the value of the others.