Question

If the vectors (i +j+k) and 3î form two sides of
a triangle, then 3rd side of the triangle can be :
(1) root 18 unit
(2) root 6 unit
(3) 3/root2 unit
(4) both 1 & 2


*KINDELY PLEASE PROVIDE ME WITH THE METHOD*​

Answer 1

Answer:

root 18 units

a+b+c=0

a=3i,b=i+j+k,

a+b+c=0

• c= -(4i+ j+ k)
• |c|=√18 units