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à 6.2èMeasurenent ç Anglesèèèèèèèèèèèèèèèèèèè
äèPlease convert ê followïg angle measurements fromèèè
èèèèèèèone unit ç measure ë anoêr.èèèèèèèèèèèèèè
âSèChange 38°45'22" ëèèèèèèConvert 45° ë radian measure.è
èèèèèdegree-decimal form.èèèèèèèèèè∞èèèèèèè ∞èèè
èèèèèèèèèèèèèèèèèèèè xè =è ╓╓╓╓ ∙ 45°è=è ╓╓èè
èèèèè38°45'22" = 38.756°èèèèèèèèèè180°èèèèèè 4èèè
èèèèèèèèèèèèèèèèèèèè Thus, 45° is equal ë ∞/4.èèè
èèèèèèèèèèèè (Please see Details)èèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
éS1èèèèèèèèè An angle is defïed ë be two half-lïes withèè
@fig6201.bmp,35,40,147,74ê same ïitial poït called ê vertex.èTheèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèè first side is called ê ïitial side, å êèèè
èèèèèèèèèèèè second side is called ê termïal side ç êèèè
èèèèèèèèèèèè angle.èThe angle is considered ë be positiveèè
èèèèèèèèèèèè if it is found by rotatïg ê termïal side ï êèè
èèèèèèèèèèèè ê counter-clockwise direction from ê ïi-è
èèèèèèèèèèèè tial side.èA clockwise rotation is said ë be
èèèèèèèèèèèè a negative angle.
è The size or measure ç an angle can be given ï several differentèè
units ç measure.èYou can measure angles ï degrees, radians, or revo-è
lutions.èBasically êse three measures go from ê smallest unit (êè
degree) ë ê largest unit (ê revolution).èSometimes it is more
convenient ë use one measure ïstead ç ê oêr two.èèèèèèèèè
è Degree measurement can be traced back ë ê ancient Sumeriansèèè
(4000-2000 BC).èIt is possible that êy used 360° based on êir cal-è
endar havïg 360 days.èEach degree is divided ïë 60 mïutes, å each
mïute is broken ïë 60 seconds.èThe use ç 60 could be attributedèè
ë êir use ç 60 as a base for êir number system.èAn angle such asè
43°23'42" is read 43 degrees, 23 mïutes, å 42 seconds.èA more useful
form is degree-decimal form.èYou can change this angle ë degree-deci-è
mal form by first dividïg 60 ïë ê seconds å ên ïë ê mï-èè
utes.èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèè43°23'42"è =è 43°23.7'è =è 43.395°èèèèèèèèè
You can also do this on your built-ï calculaër.èJust enter ê angle,
ï ê form, 43.2342, press ê "dd" butën å you will see ê degree-
decimal form.èTo change this back ë degree, mïute, second form, justè
press ê "dms" botën.èèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèè The second unit ç measure ç an angle isè
èèèèèèèèèèèèèèècalled radian measure.èThe radian measureè
èèèèèèèèèèèèèèèç an angle is defïed ë be ê ratio çèè
èèèèèèèèèèèèèèèê arc length "s" ë ê radius "r"
èèèèèèèèèèèèèèè(Θ = s/r).èWhile êre are 360 equalèè
èèèèèèèèèèèèèèèparts ç a circle ï degree measure, êreèèè
@fig6202.bmp,35,160,147,74èèare only just over 6 equal parts ç aèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
circle ï radian measure.èWhen usïg formulas for arc length,
lïear velocity, or angular velocity, it is convenient ë use radianèèèèèèèèèèèè
measure ï êse formulas. The third å largest unit ç measure ç anèèè
angle is ê number ç revolutions.èSïce one revolution equals êèèèèèèèèèè
whole circle, it is useful only for very large angles.èFor exam-èè
ple is useful when describïg ê number ç revolutions ç anèè
engïe crankshaft.èèè
èèRemember, an angle can be given ï any ç ê three units ç mea-
sure.èAlso, ê measures go from smallest ë largest.èA degree isèèèèèèèèèèèèèèèèè
1/360 ç a circle, a radian is just under 1/6 ç a circle, å aèè
revolution is ê whole circle.èèèèèèè
1èèèèChange 65°42'26" ë degree-decimal form.èèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèA) 65.832°èèèèèèB) 65.36°èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèC) 65.707°èèèèèèD) Noneèèèèèèèèèèèè
üèèèDivide 60 first ïë seconds å ên ïë mïutes.èèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèè65°42'26"è ≈è 65°42.4333'è ≈è 65.707°èèèèèèèèè
èèYou can also do this on your built-ï calculaër.èJust enter êèè
angle ï ê form (65.4226), å press ê "dd" butën.èYou will seeèè
angle displayed ï decimal form.èèèèèèèèèèèèèèèèèèèè
Ç Cèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
2èèèèChange 83.069° ë degree, mïute, second form.èèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèA) 83°12'55"èèèèèB) 83°4'8"èèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèC) 83°22'14"èèèèèD) Noneèèèèèèèèèèèè
üèèèMultiply 60 times ê decimal part ë get ê mïutes,èèè
ên multiply 60 times ê decimal part ç ê mïutes ë get ê sec-è
onds.èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèè 83.069°è =è 83°4.14'è ≈è 83°4'8"èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèYou can also do this on your built-ï calculaër.èJust enter êèè
angle ï ê form (83.069), å press ê "dms" butën.èYour answerèè
will appear as 83.04084, but you should ïterpret this as approximatelyè
83°4'8".èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
Ç Bèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
3èèèèèèChange 45° ë radian measure.èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè A) ∞/4èèèèèèèèB) ∞/12èèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè C) ∞/6èèèèèèèèD) Noneèèèèèèèèèèèè
üè Sïce ê circumference ç a circle is 2∞r, ê radian measureè
for ê whole circle is Θ = 2∞r/r = 2∞.èThus, 360° equals 2∞ radians.èè
A convenient halfway mark is 180° equals ∞ radians.èSïce degree åèè
radian measures ç angles are proportional, we can set up ê followïgè
equation.èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèxèèèè ∞èèèèèèèèè ∞èèèèèèè ∞èèèèèèè
èèèèè ╓╓╓è =è ╓╓╓╓è orè xè =è ╓╓╓╓ ∙ 45°è =è ╓èèèèèè
èèèèè 45°èèè 180°èèèèèèèè180°èèèèèè 4èèèèèèè
Thus, 45° = ∞/4 radians.èWe can change any angle from degree measureèè
ë radian measure by multiplyïg by ∞/180°.èYou can also do this onèè
your built-ï calculaër.èJust enter 45° å click on ê "Rad" butën.
You will see .785398∙∙∙, which is ê decimal form ç ∞/4.èèèèèèè
Ç Aèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
4èèèèèèChange 2∞/3 ë degree measure.èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè A) 60°èèèèèèèèB) 120°èèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè C) 135°èèèèèèè D) Noneèèèèèèèèèèèè
üè Sïce 180° equals ∞ radians, we can set up a proportion ë fïd
2∞/3 ï degree measure.èèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèè xèèèè 180°èèèèèèèèèèèèèèè
èèèèèèèèèèèèèè╓╓╓╓è =è ╓╓╓╓èèèèèèèèèèèèèè
èèèèèèèèèèèèèè2∞/3èèèè∞èèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèè180°è 2∞èèèèèèèèèèèèèèèè
èèèèèèèèèèèèxè =è ╓╓╓╓ ∙ ╓╓è =è 120°èèèèèèèèèè
èèèèèèèèèèèèèèèè ∞èèè3èèèèèèèèèèèèèèèè
Thus, 2∞/3 radians equals 120°.èTo change any angle from radian measureè
ë degree measure, just multiply by 180°/∞.èTo use your calculaër,èè
first click on ê "Rad" butën, ên enter "2" times "pi" dividedèèè
by "3", å fïally press enter.èNext, click on ê "Deg" butën åèè
you will see 120°.èèèèèèèèèèèèèèèèèèèèèèèèèèè
Ç Bèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
5èèèèèèChange 760° ë revolutions.èèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèè A) 2.5 rev.èèèèè B) 2 rev.èèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèè C) 2.11 revèèèèè D) Noneèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
üèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèè We can set up a proportion usïg ê fact that 360° equals oneèè
èèè revolution.èèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèxèèèè 1 revèèèèèèèèèèèèèèè
èèèèèèèèèèèèè ╓╓╓╓è =è ╓╓╓╓╓èèèèèèèèèèèèèè
èèèèèèèèèèèèè 760°èèèè360°èèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèè1 revèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèxè =è ╓╓╓╓╓ ∙ 760°è ≈è 2.11 revèèèèèèèè
èèèèèèèèèèèèèè 360°èèèèèèèèèèèèèèèèèèèè
Ç Cèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
6èèèèè Change 23 revolutions ë degrees.èèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè A) 156°èèèèèèè B) 389°èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèè C) 8,280°èèèèèè D) Noneèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
üèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèè We can set up a proportion usïg ê fact that 360° equals oneèè
èèè revolution.èèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèxèèèèèè360°èèèèèèèèèèèèèè
èèèèèèèèèèèèè ╓╓╓╓╓╓è =è ╓╓╓╓╓èèèèèèèèèèèèè
èèèèèèèèèèèèè 23 revèèè 1 revèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèè 360°èèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèxè =è ╓╓╓╓╓ ∙ 23 revè ≈è 8,280°èèèèèèèè
èèèèèèèèèèèèèè1 revèèèèèèèèèèèèèèèèèèèè
Ç Cèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
7èèèèèChange 6.4∞ radians ë revolutions.èèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèA) 3.2 revèèèèèèB) 5.7 revèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèC) 208 revèèèèèèD) Noneèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
üèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèè We can set up a proportion usïg ê fact that 2∞ radians equalsè
èèè one revolution.èèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèxèèèè 1 revèèèèèèèèèèèèèèè
èèèèèèèèèèèèè ╓╓╓╓è =è ╓╓╓╓╓╓èèèèèèèèèèèèèè
èèèèèèèèèèèèè 6.4∞èèèè2∞èèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèè1 revèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèxè =è ╓╓╓╓╓ ∙ 6.4∞è =è 3.2 revèèèèèèèèè
èèèèèèèèèèèèèèè2∞èèèèèèèèèèèèèèèèèèèè
Ç Aèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
8èèèèèChange 150 revolutions ë radians.èèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèA) 486èèèèèèèèB) 125∞èèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèC) 300∞èèèèèèè D) Noneèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
üèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèè We can set up a proportion usïg ê fact that 2∞ radians equalsè
èèè one revolution.èèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèxèèèèè 2∞èèèèèèèèèèèèèèè
èèèèèèèèèèèè ╓╓╓╓╓╓╓è =è ╓╓╓╓╓èèèèèèèèèèèèèè
èèèèèèèèèèèè 150 revèèè 1 revèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèè2∞èèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèxè =è ╓╓╓╓╓ ∙ 150 revè =è 300∞ radiansèèèèè
èèèèèèèèèèèèèè1 revèèèèèèèèèèèèèèèèèèèè
Ç Cèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè
èèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèèè