23 terms

Circles

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C=2∏r or C=∏d
circumference formula
360
sum of central angles
minor arc
arc that is less than 180°
formula to find an arc length
their corresponding chords are congruent
two minor arcs are congruent if and only if...
bisects
BA ____?____ VT
they are equidistant from the center
two chords are congruent if and only if...
the intercepted arc for ∠B
What is the red line?
∠ABC= ½(mADC)
How would you find ∠ABC?
2(∠ABC)=mADC
How would you find mADC?
then the angles are congruent
if two inscribed angles of a circle intercept congruent arcs or the same arc...
then its opposite angles are supplementary
If a quadrilateral is inscribed in a circle...
then it is perpendicular to the radius drawn to the point of tangency
If a line is tangent to a circle..
then the line is tangent to the circle
If a line is perpendicular to a radius...
they are congruent
what is the relationship between 2 tangent lines that meet at a point in the exterior of a circle
m∠1= ½(mAC + mBD)
how would you find m∠1
then the measure of each angle formed is half the measure of the intercepted arc
If a secant and a tangent intersect at the point of tangency...
m∠A= ½(mDE-mBC)
how would you find ∠A (2 secants)
m∠A= ½(mDC-mBC)
how would you find ∠A (Secant-tangents)
m∠A= ½(mBDC-mBC)
how would you find ∠A (2 tangents)
AE×EC=BE×ED
formula for finding the lengths of the segments of intersecting chords
AB×AC=AE×AD
formula for finding the lengths of the segments of secant segments that intersect
WX²=WZ×WY
formula for finding the lengths of the segments of tangent and secant segments that intersect