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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