Upload
godfrey-watkins
View
212
Download
0
Embed Size (px)
Citation preview
Are you ready? We heard you were going to make a few note cards - and then there might
be a short quiz. Have fun!!
White note card
circle
The set of all points in a plane that are equidistant from a given point
center
radius
diameterchordsNamed by its center: ОD D
Colored Note card
Circle formulas
Circumference: 2rArea: r²
Arc - part of a circle
Arc measure: a) degrees: equal to the measure of the
central angleb) length: central angle arc length
360° circumference =
Central angle
Major arc
Minor arc
QUIZ
1.Draw circle E. Draw and label a radius, diameter, and a chord that is not a diameter.
2.Find the exact circumference and area of circle Q.
3.Name a minor arc in the circle.
4.Name a major arc in the circle.
5.Find the arc length of BC.
A B
C
Q95°
14 cm
Colored note card
Angles in circles
Central angle • vertex is center of circle• sides are radii• measure is equal to arc
85°
85°
Inscribed angle• vertex is on circle• sides are chords• measure is half the arc
43°
86°
Colored note card
Diameters and chords
congruent chords are equidistant from center
congruent chords = congruent arcs
diameter to chord – diameter bisects chord and arc
One more problem! Find the arc length of the minor
arc.
43°
4 cmcentral angle arc length 360° circumference
=
86360
X2 • • 4=
Think about the measure
of the arc. It’s not 43°!
86°
86°
Circumference: 2r
or 3.14?
Nice job!
X 1.91 6
More problems to do, there are, young Padawan.
Some with
factoring?
Factoring in two.
Fun in all of them.