Warm-Up Exercises ANSWER x = 60; y = 60 ANSWER x = 35; y = 35 1. Find x and y. 2.
Warm-Up ExercisesEXAMPLE 1 Find measures of arcs
RSa. RTSb. RSTc.
SOLUTION
RS is a minor arc, so mRS = m RPS = 110o.a.
RTS is a major arc, so mRTS = 360o 110o = 250o.b. –
Find the measure of each arc of P, where RT is a diameter.
c. RT is a diameter, so RST is a semicircle, and mRST = 180o.
Warm-Up ExercisesEXAMPLE 2 Find measures of arcs
A recent survey asked teenagers if they would rather meet a famous musician, athlete, actor, inventor, or other person. The results are shown in the circle graph. Find the indicated arc measures.
Survey
a. mAC
SOLUTION
a. mAC mAB= + mBC
= 29o + 108o
= 137o
Warm-Up ExercisesEXAMPLE 2 Find measures of arcs
b. mACD = mAC + mCD= 137o + 83o
= 220o
A recent survey asked teenagers if they would rather meet a famous musician, athlete, actor, inventor, or other person. The results are shown in the circle graph. Find the indicated arc measures.
Survey
SOLUTION
b. mACD
Warm-Up ExercisesEXAMPLE 2 Find measures of arcs
mADC mAC= 360o – c.
= 360o – 137o
= 223o
A recent survey asked teenagers if they would rather meet a famous musician, athlete, actor, inventor, or other person. The results are shown in the circle graph. Find the indicated arc measures.
Survey
SOLUTION
c. mADC
Warm-Up ExercisesEXAMPLE 2 Find measures of arcs
d. mEBD = 360o – mED
= 360o – 61o
= 299o
d. mEBD
A recent survey asked teenagers if they would rather meet a famous musician, athlete, actor, inventor, or other person. The results are shown in the circle graph. Find the indicated arc measures.
Survey
SOLUTION
Warm-Up ExercisesGUIDED PRACTICE for Examples 1 and 2
Identify the given arc as a major arc, minor arc, or
semicircle, and find the measure of the arc.
Warm-Up Exercises
TQ is a minor arc, so m TQ = 120o.
GUIDED PRACTICE for Examples 1 and 2
1. TQ
SOLUTION
. QRT2
SOLUTION
QRT is a major arc, so m QRT= 240o.
Warm-Up ExercisesGUIDED PRACTICE for Examples 1 and 2
. TQR3
SOLUTION
TQR is a semicircle, so m TQR = 180o.
. QS4
SOLUTION
QS is a minor arc, so m QS = 160o.
Warm-Up ExercisesGUIDED PRACTICE for Examples 1 and 2
. TS5
SOLUTION
TS is a minor arc, so m TS = 80o.
. RST6
SOLUTION
RST is a semicircle, so m RST = 180o.
Warm-Up ExercisesEXAMPLE 3 Identify congruent arcs
Tell whether the red arcs are congruent. Explain why or why not.
a. b.
SOLUTION
a. CD EF because they are in the same circle and mCD = mEF
b. RS and TU have the same measure, but are not congruent because they are arcs of circles that are not congruent.
Warm-Up Exercises
c. VX YZ because they are in congruent circles and mVX = mYZ .
EXAMPLE 3 Identify congruent arcs
Tell whether the red arcs are congruent. Explain why or why not.
c.
SOLUTION
Warm-Up ExercisesGUIDED PRACTICE for Example 3
Tell whether the red arcs are congruent. Explain why or why not.
7.
AB CD because they are in congruent circles and mAB = mCD .
SOLUTION
Warm-Up ExercisesGUIDED PRACTICE for Example 3
Tell whether the red arcs are congruent. Explain why or why not.
8.
SOLUTION
MN and PQ have the same measure, but are not congruent because they are arcs of circles that are not congruent.
Warm-Up ExercisesDaily Homework Quiz
Describe each figure as a minor arc, major arc or a semicircle. Find the arc measure.
1. BC
ANSWER minor arc, 32o
Warm-Up ExercisesDaily Homework Quiz
2.
Describe each figure as a minor arc, major arc or a semicircle. Find the arc measure.
CBE
ANSWER major arc, 212o
Warm-Up ExercisesDaily Homework Quiz
3.
Describe each figure as a minor arc, major arc or a semicircle. Find the arc measure.
BCE
ANSWER semicircle, 180o
Warm-Up ExercisesDaily Homework Quiz
4.
Describe each figure as a minor arc, major arc or a semicircle. Find the arc measure.
BCAEExplain why =~ .
ANSWER
BCAE =~
m AFE = m BFC because the angles are vertical angles, so AFE BFC.Then arcs and are arcs that have the same measure in the same circle. By definition .
=~AE BC