The three vectors 7i−11j+k,5i+3j−2k and 12i−8j−k form the sides of
no ∆
an isosceles ∆
right angled ∆
equilateral ∆
|→AB|=171,|→BC|=38,|→AC|=209⇒right angle d Δ
The points A (1, 1), B (-1, 1) and the origin form the vertices of?