INDAH YULIANI KELAS 8A SMPN2 WAY SEPUTIH

indah yuliani

Jumat, 22 April 2011

soal matematika keliling bangun datar

$Jika\ \pi =\frac{22}{7},\ keliling\ daerah\ yang\ diarsir\ pada\ gambar\ di\ bawah\ ini\\adalah\ ....$

$a.\ \ 28\ cm\ \ \ \ \ \ \ \ \ \ b.\ \ 44\ cm\ \ \ \ \ \ \ \ \ \ c.\ \ 58\ cm\ \ \ \ \ \ \ \ \ \ d.\ \ 72\ cm\ \ \ \ \ \ \ \ \ \ e.\ \ 100\ cm$
Jawaban: d
$Keliling\ daerah\ yang\ diarsir\\=4\times seperempat\ keliling\ lingkaran+4\times garis\ datar\\=keliling\ lingkaran+4\times garis\ datar\\= 2\pi r+4\times 7\\=2\times \frac{22}{7}\times 7+28\\=44+28\\=72\ cm$