Question

Aflați aria dreptunghiului ABC, dacă: a)A(2;6),B(2;-1) ,C(8;-1); b)A(-2;4),B(-2;-5),C(10;4)

Answer 1

$a) \it\\ \\ AB^2=(2-2)^2+(-1-6)^2=49 \Longrightarrow AB = 7\\ \\ BC^2=(8-2)^2+(-1+1)^2=36 \Longrightarrow BC = 6\\ \\\\\mathcal{A}=AB\cdot BC=7\cdot6=42$