REVIEW ON CIRCLES 6 0 Defining Circles

REVIEW ON CIRCLES

6. 0 Defining Circles Objectives: 1. Define a circle and related terms. 2. Identify parts of a circle.

circle - set of all points in a plane at a given distance from a given point in the plane

Parts of a Circle:

radius - segment from point on circle to circles center

center - point in middle of circle with letter next to it

Circles are named by their center point.

This circle A.

What is the name of the circle below?

Circle N

congruent circles - circles with the same radius

These circles are congruent.

arc of a circle - two points on the circle and the unbroken part between the two points

arc of a circle endpoints - the two points that define an arc

NAMING ARCS An arc is named by its endpoints.

THREE TYPES OF ARCS: semicircle - arc whose endpoints are a diameter (half a circle)

THREE TYPES OF ARCS: semicircle - named using three points on the arc; endpoints listed first and last

THREE TYPES OF ARCS: The blue dashed arc is arc AOB or symbolically. . .

True or False The name of the orange arc below is…. .

True or False FALSE…it is

THREE TYPES OF ARCS: minor arc - arc less than a semicircle

THREE TYPES OF ARCS: minor arc - named using the two endpoint letters

THREE TYPES OF ARCS: The blue dashed arc is arc YZ or symbolically. . .

True or False The name of the orange arc below is…. .

True or False FALSE. It is…. .

THREE TYPES OF ARCS: major arc - arc greater than a semicircle

THREE TYPES OF ARCS: major arc - named using three points on the arc with endpoints listed first and last

THREE TYPES OF ARCS: major arc - named using three points on the arc with endpoints listed first and last

THREE TYPES OF ARCS: The blue dashed arc is arc YXZ or symbolically. . .

True or False The name of the orange arc below is…. .

True or False FALSE

Open books to page 307. With one partner, work on Investigation 6. 1. Write definitions for each term.

chord A segment whose endpoints are on the circle.

chord AB is a chord.

diameter A chord that goes through the center of a circle.

diameter CD is a diameter.

secant -line that goes through two points of a circle.

secant -line m is a secant

tangent -line that touches circle at only one point

tangent -line p is a tangent

inscribed angle -angle made of two chords

inscribed angle - ABC and BCD are inscribed angles

central angle -angle made of two radii

central angle - COD is a central angle

Name each circle part as either a chord, diameter, secant, tangent, or inscribed angle.

tangent line

chord

secant

DOA central angle

diameter

inscribed angle

Classwork/Homework