Question

In reperul cartezian xOy se considera punctele A(-2,0) , B(2,0) si C(0,3). Calculati aria triunghiului ABC

Answer 1

Calculezi distantele intre AB, BC, CA. De exemplu distanta de la A la B este 
√(x$x_{A} -x_{B}$)² + ($Y_{A}-Y_{B}$)²

Aria o poti afla cu formula lui heron 

Answer 2

$A= \frac{1}{2}*|delta|$

delta=[tex] \left[\begin{array}{ccc}1&1&1\\-2&2&0\\0&0&3\end{array}\right] = 6+0+0-(0+0-6)=6+6=12[/tex]

$A= \frac{1}{2}*|12|= \frac{12}{2} =6$