Question

If a(p, q + r), b(q, r + p) and c(r, p + q) are points then area of triangle abc

Answer 1

ar(ABC)=1/2{p[(r+p)-(p+q)]+q[(p+q)-(q+r)]+r[(q+r)-(r+p)]}
=1/2[p(r-q)+q(p-r)+r(q-p)]
=1/2[pr-pq+pq-qr+qr-pr]
=0