Question

Дано: ΔABC. AB = 9 см, CK = 8 см, AC = 14 см, BD ⊥ AC. CK ⊥ AB. Найти BD.

Answer 1

$s = \frac{ah}{2}$

$s = \frac{AB \times CK}{2}$

$s = \frac{9 \times 8}{2} = 36$

$h = \frac{2S}{a}$
$BD = \frac{2S }{AC} = \frac{2 \times 36}{14} ≈ \: 5.1$