(Q18) Find the area of the triangle formed by the points(0,0) , (4,0) , (4,3) by using Heron's formula.

The given points are O (0,0) , A(4,0) and B(4,3)

That the sides

OA = √(( - )2 + ( - )2)

    = √ =

OB = √(( - )2 + ( - )2)

    = √ =

AB = √(( - )2 + ( - )2)

    = √ =

Let a = 4, b = 5 and c = 3 then

S =
a+b+c
2
  = 
++
2
   = 

Herons formula

∆ = √(S(S-a)(S-b)(S-c))

  = √( × ( - 4) × ( - 5) × ( - 3))

  = √ =

The area of the given triangle is 6 sq.units.