Geometry 11.1 Riding a Ferris Wheel

11.1 Introduction to Circles Objectives Review the definition of line segments related to a circle such as chord, diameter, secant and tangent Review definitions of points related to a circle such as center and point of tangency Review the definitions of angles related to a circle such as central angle and inscribed angle Review the definitions of arcs related to a circle such as major arc, minor arc and semicircle Prove all circles are similar using rigid motion

Introduction to Circles http://ed.ted.com/lessons/why-are-manhole-covers-round-marc-chamberland

Problem 1: Going Around and Around Read together #1 Together Radii: Plural of radius – More than one radius. Chord: A segment connecting two points on a circle. Diameter: A chord that runs through the center.

Problem 1: Going Around and Around Secant of a Circle: A line that intersects a circle at exactly two points. Tangent of a Circle: A line that intersects a circle at exactly one point. The intersection is called the Point of Tangency. Collaborate 2-7 (4 Minutes)

Problem 1: Going Around and Around Together #8 (We will go across each row) X X X X X X X X X X X

Problem 2: Sitting on the Wheel Central Angle: The vertex of the angle is at the center of the circle. Inscribed Angle: The vertex of the angle is on the circle. Together #1

Problem 2: Sitting on the Wheel Arc of a Circle: A fraction of the circumference Major Arc: The larger fraction of the circumference Minor Arc: The shorter fraction of the circumference Semicircle: Exactly half of a circle Collaborate 2 a-f (5 Minutes)

Problem 2: Sitting on the Wheel To name a minor arc, use the two endpoints. 𝐴𝐵 To name a major arc, name a third point between the endpoints along the way. 𝐴𝑋𝐵 B A X

Problem 2: Sitting on the Wheel

Talk the Talk Pg. 848 Collaborate 1-7 (3 Minutes)

D F E A B C

Formative Assessment Skills Practice 11.1 Vocabulary Pg. 779 (1-12)