1. Day 1

2. Tangent
Chord
VOCAB
Inscribed Angle
Central Angle
Secant

3. Chord: A segment with endpoints that are on the circle
Tangent: A line that intersects the circle in exactly one point (touches, but does not cross through)
Inscribed Angle: An angle that has a vertex on a circle and sides that contain chords of the circle
Central Angle: An angle that intersects a circle in two points and has its vertex at the center of the circle
Secant: Any line that intersects a circle in exactly two points

4. Major Arc Minor Arc A Minor Arc = 𝐴𝐵 Major Arc = 𝐴𝐶𝐵 Named by
two endpoints
Measures
between 0°<𝜃<180°
Named by
Three points (two endpoints
with one in between)
Measures 𝜃>180°
Major Arc B E C
Semicircle = 𝐵𝐷𝐶
Circle = ⊙E
Named by its “Center”
“Circle E”
Measures exactly
𝜃=360°
Named by
Three points (two endpoints
with one in between)
Measures exactly
𝜃=180° D

5. Inscribed Quadrilateral Inscribed Quadrilateral:F F
𝑬𝑿 𝟏:
VOCAB:
<𝐶𝐹𝐷 is an INSCRIBED ANGLE
<𝑪𝑭𝑫= 𝟏 𝟐 𝒎 𝑪𝑫
Inscribed Quadrilateral A B C D B C E
𝑉𝑂𝐶𝐴𝐵:
<𝐶𝐸𝐷 is a CENTRAL ANGLE
<𝑪𝑬𝑫=𝒎 𝑫𝑪
𝑬𝑿 𝟐:
Inscribed Quadrilateral:
Opposite Angles are
SUPPLEMENTARY!
Central Angle D

6. 𝐄𝐗 𝟏: 𝟗𝟎°= 𝒎 𝑪𝑫 If <𝑪𝑭𝑫=𝟒𝟓°, 𝒇𝒊𝒏𝒅 𝒎 𝑪𝑫 <𝑪𝑭𝑫= 𝟏 𝟐 𝒎 𝑪𝑫C D F
If <𝑪𝑭𝑫=𝟒𝟓°, 𝒇𝒊𝒏𝒅 𝒎 𝑪𝑫
𝟒𝟓°
<𝑪𝑭𝑫= 𝟏 𝟐 𝒎 𝑪𝑫
𝟒𝟓= 𝟏 𝟐 𝒎 𝑪𝑫
𝟗𝟎°= 𝒎 𝑪𝑫

7. EX 2:
If Opposite angles are supplementary in an inscribed quadrilateral, find the following measure. <𝐷=71° Find the measure of <𝐵 A B C D
<D+<B=180
71+<B=180
<B=109°