In rectangle ABCD, the sides are [math]BC=6[/math]cm and [math]CD=6\sqrt{3}[/math] cm, and the diagonals intersect at point O,[math]AC\cap BD=\left\{O\right\}[/math]. Knowing that E is the symmetric of point C with respect to B, and [math]OE\cap AB=\left\{F\right\}[/math], then:[br][*][b]1.[/b] Find the length of segment AE.[br][/*][*][b]2.[/b] Show that the perimeter of triangle BEF is less than 17 cm.[br][/*]
Find the length of segment AE.
BE=BC=6, AB=CD[br]Apply the Pythagorean Theorem to triangle ABE.[br]AE=12
Prove that F is the center of gravity in triangle AEC.
Use: AB and EO are medians in triangle AEC.
Perimeter of BEF triangle is:
Prove: [math]P_{BEF}<17[/math]
[math]6+6\sqrt{3}<17\Leftrightarrow6\sqrt{3}<11\Leftrightarrow36\cdot3<121\Leftrightarrow108<121[/math][br]True