Bài hình nâng cao

S

soicon_boy_9x

picture.php

Đặt $OA=OB=x \ \ \ \ OD=OC=y$

Theo định lí Py ta go ta có:

$x^2+x^2=2^2 \leftrightarrow x=\sqrt{2}$

$x^2+y^2=3^2 \leftrightarrow y=\sqrt{7}$

Ta có: $AC=BD=x+y=\sqrt{2}+\sqrt{7}$

$\rightarrow S_{ABCD}=\dfrac{AC.BD}{2}=\dfrac{(\sqrt{2}+
\sqrt{7})^2}{2}=\dfrac{9+2\sqrt{14}}{2}$

$CD=\sqrt{2y^2}=\sqrt{14}$

 
You must log in or register to reply here.
Top Bottom