Warm Up April 21st, 2014 Draw the diagram of the 30-60-90 triangle and label the sides. If tanB = 13/14 find the angle measure of B?

EOCT Week 14 #1

AGENDA Quiz and tests returned Notes on Circles Notes on Central Angles Practice Worksheet Homework Worksheet

Unit 3 Circles

Segments of Circles

Parts of a Circle Circle – set of all points _________ from a given point called the _____ of the circle. equidistant C center Symbol: C

CHORD: A segment whose endpoints are on the circle

Radius RADIUS: Distance from the center to point on circle P

Distance across the circle through its center Diameter DIAMETER: Distance across the circle through its center P Also known as the longest chord.

D = ? 24 32 12 r = ? 16 r = ? 4.5 6 D = ? 12 9

Use P to determine whether each statement is true or false. Q R T S True: thumbs up False: thumbs down

Secant Line: intersects the circle at exactly TWO points

a LINE that intersects the circle exactly ONE time Tangent Line: a LINE that intersects the circle exactly ONE time Forms a 90°angle with a radius Point of Tangency: The point where the tangent intersects the circle

Secant Radius Diameter Chord Tangent Name the term that best describes the notation. Secant Radius Diameter Chord Tangent

Central Section 6.2 Arcs

Central Angle : An Angle whose vertex is at the center of the circle Major Arc Minor Arc More than 180° Less than 180° ACB P AB To name: use 3 letters C To name: use 2 letters B APB is a Central Angle

Semicircle: An Arc that equals 180° To name: use 3 letters E D EDF P F

THINGS TO KNOW AND REMEMBER ALWAYS A circle has 360 degrees A semicircle has 180 degrees Vertical Angles are Equal

measure of an arc = measure of central angle 96 Q m AB = 96° B C m ACB = 264° m AE = 84°

Arc Addition Postulate B m ABC = + m BC m AB

240 260 m DAB = m BCA = Tell me the measure of the following arcs. D 140 260 m BCA = R 40 100 80 C B

CONGRUENT ARCS Congruent Arcs have the same measure and MUST come from the same circle or of congruent circles. C B D 45 45 110 A Arc length is proportional to “r”

Classwork Practice Worksheet

Homework: Practice Worksheet