Jun 27 2013

Problem (21) : Tinggi Segitiga


soal dikirim via email by inung.emka@yahoo.com

photo segitigat_zps850e149c.png
Nilai t pada gambar dibawah adalah …

Penyelesaian :

Disini kita akan memanfaatkan sifat segitiga sebangun,

Pandang \triangle ABD :

\frac{AD}{AB} = \frac{EF}{FB}

EF = \frac{AD}{AB} FB … (i)

Pandang \triangle ABC :

\frac{AB}{BC} = \frac{AF}{FE}

FE = \frac{BC}{AB} AF … (ii)

Dari pers (i) dan (ii), diperoleh :

(i) = (ii)

\frac{AD}{AB} FB = \frac{BC}{AB} AF

\frac{6}{AB} FB = \frac{12}{AB} AF

FB = 2 AF … (iii)

Substitusi pers (iii) ke pers (i), diperoleh :

EF = \frac{AD}{AB} FB

= \frac{AD}{AF+FB} FB

= \frac{6}{\frac{1}{2}FB+FB} FB

= \frac{6}{\frac{3}{2}FB} FB

= \frac{6.2}{3}

= 4

Jadi panjang t = EF = 4cm

Iklan

Tinggalkan Balasan

Isikan data di bawah atau klik salah satu ikon untuk log in:

Gravatar
Logo WordPress.com

You are commenting using your WordPress.com account. ( Logout /  Ubah )

Foto Google+

You are commenting using your Google+ account. ( Logout /  Ubah )

Gambar Twitter

You are commenting using your Twitter account. ( Logout /  Ubah )

Foto Facebook

You are commenting using your Facebook account. ( Logout /  Ubah )

Batal

Connecting to %s