Circle Geometry

CircumferenceThe entire outside of a circleduh.

Arcs: Major and MinorA section of the circumference is an arc.The shorter arc AB is the minor arc.The longer arc AB is the major arc.AB

Central vs Inscribed AnglesThe angle formed by joining the endpoints of an arc to any point on a circle is an inscribed angle.

Inquiring Mindshttp://staff.argyll.epsb.ca/jreed/math20p/circles/inscribed_central.htm

Central vs Inscribed AnglesThe inscribed angle is always half the central angle OR the central angle is always double the inscribed angle.2(

Central vs Inscribed AnglesOCBAIf

Inscribed Angle Propertieshttp://staff.argyll.epsb.ca/jreed/math20p/circles/inscribed_inscribed.htmBTEAI

Inscribed Angle PropertiesSo

Inscribed Angle PropertiesSo what would angles y and x be?What circle properties are we using?

Inscribed Angle PropertiesInscribed Angles with the same endpoints are identicalSo

Inscribed Angle Properties#1 Inscribed Angles with the same endpoints are identical, and #2 a central angle is double the inscribed angle with the same endpoints.Remember: The interior angles of a circle total 360.

Inscribed Angle PropertiesWhere can we start?Solve x? y? zWhat could we do to start filling in the angles?

501203060703020204040Heres our angle bank:

Step 1: 2 different RadiiWhere do we start? What would be step #1?

Step 1: 2 different Radii18

Step 2: Determine QA18

Step 2: Determine QA1833.94

Step 2: Determine PA1833.94

Step 2: Determine PA1833.9416.97

Step 1: Determine y33.9416.97

Step 1: Determine y16.9716.9733.94

Assignment TimePg. 410: 3-6, 11, 12, 15