Respuesta :
Answer: <CAB = 39 arcEBC = 126
Step-by-step explanation:
Rule 1: All the angles of a circle add up to equal 360
Rule 2: The arc angle and the angle are the same if the angle starts at the center of the circle
Circle 1:
<CAD + <CAB + <BAE + <EAD = 360 >Add all angles and substitute
200 + <CAB + 73 + 48 = 360 >Add numbers on left
321 + <CAB = 360 >Subtract 321 from both sides <CAB = 39
arcCDE = arcCAD + arcED
arc CDE = 200 + 48
arcCDE = 248
Circle 2:
Let's call the center O
Find: arcEBC
arcEBC = <EOC + <BOC
<DOE + <EOC + <BOC + <COD = 360 >Add all angles then substitute
123 + <EOC + 67 + 111 = 360 >Add numbers on left
<EOC + 301 = 360 >Subtract 301 from both sides
<EOC = 59
arcEBC = <EOC + <BOC
arcEBC = 59 + 67
arcEBC = 126
arcDCB = arcDC + arc CB
arcDCB = 111 + 67
arcDCB = 178
Answer:
Arc CDE = 248°
∠CAB = 39°
Arc DCB = 178°
Arc EBC = 126°
Step-by-step explanation:
Question 1
An arc is named using its endpoints. If the arc is named using three letters, the middle letter is any other point contained in the arc.
Therefore, the arc CDE is the sum of arc CD and arc DE:
[tex]\begin{aligned}\overset{\frown}{CDE}&=\overset{\frown}{CD}+\overset{\frown}{DE}\\&=200^{\circ}+48^{\circ}\\&=248^{\circ}\end{aligned}[/tex]
Therefore, arc CDE measures 248°.
As the measure of an arc is equal to the measure of its corresponding central angle, and angles around a point sum to 360°, then:
[tex]\angle CAB+\angle CAD + \angle DAE + \angle EAD = 360^{\circ}[/tex]
[tex]\angle CAB+\overset{\frown}{CD} + \overset{\frown}{DE} + \angle EAD = 360^{\circ}[/tex]
[tex]\angle CAB+200^{\circ}+ 48^{\circ} + 73^{\circ} = 360^{\circ}[/tex]
[tex]\angle CAB+321^{\circ} = 360^{\circ}[/tex]
[tex]\angle CAB=39^{\circ}[/tex]
Therefore, angle CAB measures 39°.
[tex]\hrulefill[/tex]
Question 2
An arc is named using its endpoints. If the arc is named using three letters, the middle letter is any other point contained in the arc.
Therefore, the arc DCB is the sum of arc DC and arc CB:
[tex]\overset{\frown}{DCB}=\overset{\frown}{DC}+\overset{\frown}{CB}[/tex]
The measure of an arc is equal to the measure of its corresponding central angle. Therefore:
[tex]\begin{aligned}\overset{\frown}{DCB}&=\overset{\frown}{DC}+\overset{\frown}{CB}\\&=111^{\circ}+67^{\circ}\\&=178^{\circ}\end{aligned}[/tex]
Therefore, arc DCB measures 178°.
As the measure of an arc is equal to the measure of its corresponding central angle, and angles around a point sum to 360°, then:
[tex]\overset{\frown}{DC} + \overset{\frown}{CB} + \overset{\frown}{BE} +\overset{\frown}{ED}= 360^{\circ}[/tex]
[tex]111^{\circ} + 67^{\circ} + \overset{\frown}{BE} +123^{\circ}= 360^{\circ}[/tex]
[tex]\overset{\frown}{BE} +301^{\circ}= 360^{\circ}[/tex]
[tex]\overset{\frown}{BE} =59^{\circ}[/tex]
The arc EBC is the sum of arc EB and arc BC:
[tex]\begin{aligned}\overset{\frown}{EBC}&=\overset{\frown}{EB}+\overset{\frown}{BC}\\&=59^{\circ}+67^{\circ}\\&=126^{\circ}\end{aligned}[/tex]
Therefore, arc EBC measures 126°.