Question

Find the area of a triangle, whose sides are :

18 mm, 24 mm and 30 mm

Answer 1

Sides of ∆ are
a = 18 mm
b = 24 mm
c = 30 mm

S = `(a + b + c)/2 = (18 + 24 + 30)/2`

= `72/2 = 36`

area of Δ = `sqrt(S(S - a)(S - b)(S - c))`

= `sqrt(36(36 - 18)(36 - 24)(36 - 30))`

= `sqrt(36 xx 18 xx 12 xx 6)`

= `sqrt(18 xx 2 xx 18 xx 2 xx 6 xx 6)`

= `sqrt(18 xx 18 xx 2 xx 2 xx 6 xx 6)`

= `18 xx 2 xx 6 = 216  "mm"^2`