Unit 3 angle pairs
Lesson 10 find missing angles
To find missing angles in a given figure, you need to use the following properties of angle pairs:
1. Complementary angles: Two angles are complementary if the sum of their measures is 90 degrees. To find a missing angle that is complementary to a known angle, subtract the measure of the known angle from 90 degrees.
2. Supplementary angles: Two angles are supplementary if the sum of their measures is 180 degrees. To find a missing angle that is supplementary to a known angle, subtract the measure of the known angle from 180 degrees.
3. Vertical angles: Vertical angles are formed by two intersecting lines. They are congruent (equal in measure). If you know the measure of one vertical angle, then you know the measure of its corresponding vertical angle.
4. Linear pair: A linear pair is formed by two adjacent angles that form a straight line. The sum of the measures of a linear pair is always 180 degrees. If you know the measure of one angle in a linear pair, you can find the measure of its adjacent angle by subtracting from 180 degrees.
5. Corresponding angles: Corresponding angles are formed when a transversal intersects two parallel lines. They are congruent. If you know the measure of one corresponding angle, you can find the measure of its corresponding angle.
By using these angle properties and relationships, you can calculate the measures of missing angles in a given figure.