Roboguru

Pertanyaan

Diberikan segiempat ABCD seperti pada gambar!

Panjang BC adalah... 

  1. 4 square root of 2 space cm 

  2. 6 square root of 2 space cm 

  3. 7 square root of 3 space cm 

  4. 5 square root of 6 space cm 

  5. 7 square root of 6 space cm 

M. Rochmat

Master Teacher

Jawaban terverifikasi

Pembahasan

Menentukan panjang AC menggunakan aturan sinus

table attributes columnalign right center left columnspacing 0px end attributes row cell fraction numerator AC over denominator sin space straight D end fraction end cell equals cell fraction numerator AD over denominator sin space straight C end fraction end cell row cell fraction numerator AC over denominator sin space 30 degree end fraction end cell equals cell fraction numerator 10 over denominator sin space 45 degree end fraction end cell row cell fraction numerator AC over denominator begin display style 1 half end style end fraction end cell equals cell fraction numerator 10 over denominator begin display style 1 half end style square root of 2 end fraction end cell row cell AC cross times 1 half square root of 2 end cell equals cell 1 half cross times 10 end cell row AC equals cell fraction numerator 1 half cross times 10 over denominator 1 half square root of 2 end fraction end cell row AC equals cell fraction numerator 10 over denominator square root of 2 end fraction cross times fraction numerator square root of 2 over denominator square root of 2 end fraction end cell row AC equals cell fraction numerator 10 square root of 2 over denominator 2 end fraction end cell row AC equals cell 5 square root of 2 space cm end cell end table 

Menentukan panjang BC menggunakan aturan cosinus

table attributes columnalign right center left columnspacing 0px end attributes row BC equals cell square root of AB squared plus AC squared minus 2 times AB times AC times cos space straight A end root end cell row blank equals cell square root of left parenthesis 10 square root of 2 right parenthesis squared plus left parenthesis 5 square root of 2 right parenthesis squared minus 2 times 10 square root of 2 times 5 square root of 2 times cos space 60 degree end root end cell row blank equals cell square root of 200 plus 50 minus 200 times 1 half end root end cell row blank equals cell square root of 250 minus 100 end root end cell row blank equals cell square root of 150 end cell row blank equals cell square root of 25 cross times 6 end root end cell row blank equals cell 5 square root of 6 space cm end cell end table 

Jadi, jawaban yang benar adalah D.

 

94

5.0 (3 rating)

Pertanyaan serupa

Diketahui segiempat ABCD dengan panjang sisi AD=8cm, CD=10cm, , , dan . Panjang sisi BC adalah ....

38

0.0

Jawaban terverifikasi

RUANGGURU HQ

Jl. Dr. Saharjo No.161, Manggarai Selatan, Tebet, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta 12860

Coba GRATIS Aplikasi Ruangguru

Produk Ruangguru

Produk Lainnya

Hubungi Kami

Ruangguru WhatsApp

081578200000

Email info@ruangguru.com

info@ruangguru.com

Contact 02140008000

02140008000

Ikuti Kami

©2022 Ruangguru. All Rights Reserved PT. Ruang Raya Indonesia