Jumat, 03 Februari 2012

LKS Luas Segitiga




LEMBAR KERJA SISWA (LKS)
Sekolah                           :      SMP
Mata pelajaran              :      Matematika
Kelas/Semester               :      VII/Genap
Materi Pokok                 :      Luas Segitiga
Waktu                             :      8 menit
 

Tujuan Pembelajaran:
1.      Siswa dapat menentukan rumus luas segitiga.
2.      Siswa dapat menghitung luas segitiga.
Langkah-langkah Kegiatan :
1.      Diberikan 3 buah persegipanjang yang kongruen dan 3 jenis segitiga.
2.      Tentukanlah alas dan tinggi pada tiap jenis segitiga yang bersesuaian dengan panjang dan lebar pada persegipanjang, sehingga:
·         alas segitiga (a) sama dengan panjang dari persegipanjang (p)
·         tinggi segitiga (t) sama dengan lebar dari persegipanjang (l)
3.      Bentuklah atau gambarlah setiap jenis segitiga pada masing-masing persegipanjang, kemudian tentukan alas dan tinggi segitiga yang terbentuk pada masing-masing persegipanjang
4.      Dengan menggunakan pendekatan luas persegipanjang, carilah luas segitiga (diskusikan dalam kelompokmu).
Jawab :
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               
                                                                                                                               

Kesimpulan :
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   

Kerjakanlah soal di bawah ini!
Diketahui sebuah segitiga memiliki alas = 20 cm dan tinggi = 7 cm. Berapakah luas segitiga tersebut?
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   
                                                                                                                                   


Tes
Luas Segitiga

Nama                 :                                                                                                          
No. Absen          :                                                                                                          

Kerjakanlah soal di bawah ini dengan tepat.
1.    Luas sebuah segitiga = 48 cm2 dan panjang alasnya = 16 cm.
Hitunglah tinggi segitiga tersebut!
2.    Bu Lala mempunyai kebun jeruk berbentuk segiempat seperti
gambar di bawah. Tentukan luas kebun Bu Lala!
 







2 komentar:

  1. Makasih ya, dah membantu banget!

    BalasHapus
    Balasan
    1. @yani: sama2.. :)
      Klo ada request,, tinggal komen aja..

      Hapus