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Question
Find the area of a triangle, whose sides are :
18 mm, 24 mm and 30 mm
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Solution
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`
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