Geometry, Teacher\'s Edition

TABLE1.7:(continued)

Example Angle Formula Segment Length

Angle formed by two in-

tersecting tangents

Difference of intercepted

arcs

Angle formed by two in-

tersecting secants

Difference of intercepted

arcs

Angle formed by a tan-

gent and secant intersec-

tion

Difference of intercepted

arcs

Segments of Chords, Secants, and Tangents

Pacing:This lesson should take one class period

Goal:This goal of this lesson is to explain the formulas for determining segment lengths formed by intersecting
secants and tangents.

Organize!Finish the chart began in the previous lesson.

TABLE1.8:

Example Angle Formula Segment Length

Tangent Chord^12 (intercepted arc) N/A

Angles formed by two in-

tersecting chords

Sum of intercepted arcs a∗b=c∗d

whole secant 1 ∗ external

part 1 =whole secant 2 ∗ex-

ternal part 2

1.9. Circles