Question

prove that (6,1),(10,9)&(-6,7) forn a righf angle triangle

Answer 1

let P(6,1),Q(10,9)&R(-6,7)
PQ^2=(10-6)^2+(9-1)^2
=16+64=80
QR^2=(10+6)^2+(9-7)^2
=256+4=260
PR^2=(6+6)^2+(1-7)^2
=144+36=180
clearly,80+180=260
PQ^2+PR^2=QR^2
By pythagorus theorem,PQR is rt angled at P