12 Chapter Review

Connecting BIG ideas and Answering the Essential Questions

1 Reasoning and Proof The measure of an arc equals the measure of its central angle. You can use this angle and arc to prove relationships of other angles and arcs. 2 Measurement Segments intersecting circles form angles and intercepted arcs. You can find some missing measures using given information and appropriate formulas.	Tangents, Chords, and Arcs (Lessons 12-1, 12-2)	Locus: A Set of Points (Lesson 12-6) A locus is a set of points, all of which meet a stated condition.
	Angles and Circles (Lessons 12-3, 12-4) Image Long Description	Segment Lengths (Lesson 12-4) a · b = c · d eh middle dot , b equals . c middle dot d Image Long Description ( w + x ) w = ( y + z ) y open w plus . x close w equals . open y plus z close y ( p + q ) p = t 2 open p plus . q close p equals . t squared
3 Coordinate Geometry You can use the center and the radius to write an equation of a circle.	Circles in the Coordinate Plane (Lesson 12-5) ( x − h ) 2 + ( y − k ) 2 = r 2 open x minus . h , close squared , plus , open y minus . k , close squared , equals , r squared

Chapter Vocabulary

• chord (p. 771)
• inscribed angle (p. 780)
• intercepted arc (p. 780)
• locus (p. 804)
• point of tangency (p. 762)
• secant (p. 791)
• standard form of an equation of a circle (p. 799)
• tangent to a circle (p. 762)

Use the figure to choose the correct term to complete each sentence.

1. E F ↔ modified e f with left right arrow above  is (a secant of, tangent to) ⊙ X . circle dot x .
2. D F ¯ d f bar  is a (chord, locus) of ⊙ X . circle dot x .
3. Δ A B C cap delta eh b c  is made of (chords in, tangents to) ⊙ X . circle dot x .
4. ∠ D E F angle d e f  is an (intercepted arc, inscribed angle) of ⊙ X . circle dot x .

5. The set of all points equidistant from the endpoints of C B ¯ c b bar  is a (locus, tangent).

   

Table of Contents