Question

Calculati aria triunghiului ABC, daca :
c) AB = 6 cm,AC = 9 cm,BC = 12 cm
Va roggggg

Answer 1

Folosim formula lui Heron.

$p= \frac{AB+AC+BC}{2}= \frac{6+9+12}{2}= \frac{27}{2} (cm)\\ \\ A_{ABC} = \sqrt{p(p-AB)(p-AC)(p-BC)}= \\ = \sqrt{ \frac{27}{2}* (\frac{27}{2}-6) * (\frac{27}{2}-9)* (\frac{27}{2}-12) } = \\ = \sqrt{ \frac{27}{2}* \frac{15}{2}* \frac{9}{2}* \frac{3}{2} } = \\ = \frac{729}{4} \sqrt{ 15} (cm ^{2} )$