Measuring Angles

1. Geometry/Trig 2 Name: _________________________ Angles – Notes & Exploration Date: __________________________ Angle Angle: ____________________________________________________________ __________________________________________________________________ • The two rays are called the ____________. • The shared endpoint is called the __________. Naming Angles: We name an angle ___________________________________________________. Acceptable: ______________________ Unacceptable: ____________________ Order Matters! _____________________________________________________. Notation C A T Alternate Notation Sometimes, you can name an angle just with the vertex. This angle could be ______. C Sometimes using only one letter may not be __________ __________________; it may refer to more than one angle. IF THERE IS ANY DOUBT, USE _____LETTERS! A T We also may name angles with numbers. Angle Interior T Angle Interior: _______________________________ ___________________________________________ H E Measuring Angles Measuring Angles: We measure angles using a ________________. The units for angle measurement is either degrees or radians. In this class we will use degrees. Symbol for degree: ____________ Measure of an angle: ___________

2. J D A G K H F B C P R S L T W Q M N

3. Types of Angles Acute Angle Obtuse Angle Definition: ______________________ _______________________________ Diagram: Definition: _______________________ ________________________________ Diagram: Right Angle Straight Angle Definition: ______________________ _______________________________ Diagram: Definition: _______________________ ________________________________ Diagram: Angle Addition Postulate Adjacent Angles: ____________________________________________________ __________________________________________________________________ D ÐABD and ÐDBC ______________________________________ ___________________________________________________ ÐABD and ÐABC ______________________________________ ___________________________________________________ A B C Angle Addition Postulate If point B lies _____________________ _________________________________ Angle Addition Postulate – Special Case If ÐDGF is ______________________ ______________________________________________________________ B A Q C D G F

4. Congruent Angles & Angle Bisector Congruent Angles: _______________ ______________________________ Complementary Angles: Two angles whose measures sum to ______. (They may be non-adjacent (_____________) or adjacent (__________________)). Diagrams: Complementary Angles Angle Bisector: _________________ ______________________________ Supplementary Angles Supplementary Angles: Two angles whose measures sum to ______. (They may be non-adjacent (_____________) or adjacent (__________________)). Diagrams: Vertical Angles Vertical Angles: Two _____________ ____________________________________________________________ Example: ______________________ Diagram: Vertical Angle Theorem: __________ _____________________________