Pertanyaan

Perhatikan gambar berikut! Jika luas juring AOB=50cm 2 , tentukan: a. luas juring COD , b. jari-jari lingkaran, dan c. panjang CD ⌢ !

Perhatikan gambar berikut!

Jika luas juring $AOB = 50 cm^{2}$ , tentukan:

a. luas juring $COD$ ,

b. jari-jari lingkaran, dan

c. panjang $CD ⌢$ !

N. Ayu

Master Teacher

Mahasiswa/Alumni Universitas Negeri Padang

Jawaban terverifikasi

Jawaban

panjang adalah .

panjang

adalah

Pembahasan

Perhatikan perhitungan berikut ini. a.luas juring , yaitu: Jadi, luas juring yaitu . b. jari-jari lingkaran, yaitu: Jadi, jari-jari lingkaran adalah . c.panjang , yaitu: Jadi, panjang adalah .

Perhatikan perhitungan berikut ini.

a. luas juring , yaitu:

$begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell fraction numerator text ∠AOB end text over denominator text luas juring AOB end text end fraction end cell equals cell fraction numerator text ∠COD end text over denominator text luas juring COD end text end fraction end cell row cell fraction numerator 75 degree over denominator 50 end fraction end cell equals cell fraction numerator 60 degree over denominator text luas juring COD end text end fraction end cell row cell text luas juring COD end text end cell equals cell fraction numerator 60 degree times 50 over denominator 75 degree end fraction end cell row cell text luas juring COD end text end cell equals 40 end table end style$

Jadi, luas juring yaitu .

b. jari-jari lingkaran, yaitu:

$begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell text luas juring COD end text end cell equals cell fraction numerator angle text COD end text over denominator 360 degree end fraction cross times l text uas lingkaran end text end cell row cell text luas juring COD end text end cell equals cell fraction numerator 60 degree over denominator 360 degree end fraction cross times πr squared end cell row 40 equals cell fraction numerator 60 degree over denominator 360 degree end fraction cross times 3 comma 14 cross times straight r squared end cell row cell fraction numerator 40 cross times 360 degree over denominator 60 degree cross times 3 comma 14 end fraction end cell equals cell straight r squared end cell row cell fraction numerator 40 cross times 6 over denominator 3 comma 14 end fraction end cell equals cell straight r squared end cell row cell fraction numerator 240 over denominator 3 comma 14 end fraction end cell equals cell straight r squared end cell row cell square root of fraction numerator 240 over denominator 3 comma 14 end fraction end root end cell equals straight r row cell 8 comma 74 end cell equals straight r end table end style$

Jadi, jari-jari lingkaran adalah .

c. panjang , yaitu:

$begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell text panjang end text space stack text CD end text with overparenthesis on top end cell equals cell fraction numerator angle text COD end text over denominator 360 degree end fraction cross times text keliling lingkaran end text end cell row blank equals cell fraction numerator 60 degree over denominator 360 degree end fraction cross times 2 πr end cell row blank equals cell fraction numerator 60 degree over denominator 360 degree end fraction cross times 2 times 3 comma 14 times 8 comma 74 end cell row blank equals cell 1 over 6 cross times 6 comma 28 times 8 comma 74 end cell row blank equals cell 9 comma 15 end cell end table end style$

Jadi, panjang adalah .