Question

Area of triangle whose side is 60cm,100cmand140cm

Answer 1

Sides : a = 60cm, b = 100cm, c = 140cm.

Perimeter = P = 60 + 100 + 140 = 300cm

∴Semi-Perimeter = s = P÷2 = 150cm.

By Heron's formula,

A = √s (s-a) (s-b) (s-c)

   = √ 150 × (150 - 60) × (150 - 100) × (150 - 140)

  = √ 150 × 90 × 50 × 10

  = √ 3 × 5 × 10 × 3 × 3 × 10 × 5 × 10 × 10

  = √ 3 × 3 × 3 × 5 × 5 × 10 × 10 × 10 × 10

  = 3 × 5 × 10 × 10 √3

  = 1500√3 cm²

        (OR)

  = 1500 × 1.732

  = 2598cm².