Question

Find area of triangle whose sides are P(-5,-3) ,Q(-4,-6) and S (1,2)

Answer 1

$\huge\underline\mathcal\green{Question}$

Find area of triangle whose sides are P(-5,-3) ,Q(-4,-6) and S (1,2)

$\huge\underline\mathcal\green{Solution}$

In ∆PQS

$\implies\sf \frac{1}{2}(x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)$

$\implies\sf \frac{1}{2}(-5(-6-2)+(-4)(2-(-3))+1(-3-(-6))$

$\implies\sf \frac{1}{2}(-5\times{(-8)}+(-4)\times{5}+3)$

$\implies\sf \frac{1}{2}(40-20+3)$

$\implies\sf \frac{1}{2}\times{23}=11.5sq.unit$