Question

The perimeter of the triangle whose vertices have the position vectors (I+j+k),5i+3j-3k) and (2i+5j+9k) is

Answer 1

Given :

The vertices of a triangle are

  a = i + j + k

  b = 5i + 3j - 3k

  c = 2i + 5j + 9k

To find :

The perimeter of the triangle

Solution :

• The perimeter of triangle = a+b+c

                     = ( i + j + k) +(5i + 3j - 3k) + (2i + 5j + 9k)

                     = 8i + 9j +7k

• perimeter = √(8² + 9² + 7²)

                = √64 + 81 + 49

                = √194     =13.92 cm

The perimeter of the triangle is 13.92 cm