Chapter 6 Circle Theorems And Puzzles Flashcards
Secant line
A segment that intersects the circle twice
Tangent line
A line that intersects the circle only at one point
Point of tangency
The point where the tangent line intersects the circle
Semicircle Arc
1) Half the circle
2) 180°
3) Three letters to label ABC (with arc notation over them)
Minor arc
1) Less than 180°
2) Two letters to label AB (with arc notation)
Major arc
1) Greater than 180°
2) Use three letters to label ABC (with arc notation)
Inscribed Angle
1) An angle with the vertex on the circle
2) The angle is half the arc measure
Central angle
1) An angle with the vertex on the center
2) The angle is congruent to the arc measure
Inscribed right triangle
The angle inscribed in a semicircle is a right angle
Congruent chords
Congruent chords make congruent arcs
Angle created by a tangent and a chord
1) The chord and tangent meet at the point of tangency
2) The chord/tangent angle it half the arc it subtends. (Cuts out)
Perpendicular radius and chord
A radius is perpendicular to the chord and bisects the chord and the arc the chord subtends.
Two arcs, chords, and radii
Chords that are the same distance from the center are congruent, along with their arcs and radii.
Radius and tangent line
The radius is perpendicular to the tangent line at the point of tangency.
Inscribed quadrilateral
Opposite angles are supplementary \_\_\_\_\_\_\_\_\_\_\_\_ |180-x 180-y| | | |y x| ----------------
Twin tangents
Tangent from the same point are congruent.
Two chord lengths
ab=cd
Two secants length
Outsidewhole thing=Outsidewhole thing (se=ca)
1 tangent, 1 secant length
t^2= outsidewhole length
Or
t^2= se
Smiley face (2 tangent, 2 radii)
The angle created by the two radii is the same as the arc created by the two tangents. The tangent angle is x, the arc and the central angle is 180-x.
Circumference
C=2rPi
C=dPi
Pi=c/d (d is the number of times the circle)
Arc length
A= x°/360°*2(Pi)r
Chord
A segment with end points on the circle
Two chords angle
Angle1=(k+j)/2
other format vanished, leaving just m for no reason.
Two secants angle
Angle1=(k-j)/2
1 tangent, 1 secant angle
Angle1=(k-j)/2
2 tangents angle
Angle1=(k-j)/2