Question

The perimeter of a triangle is 84 cm and side are in the ratio 13:14:15. Find the area of the triangle.

Answer 1

let the ratios be 13x, 14x and 15x

perimeter of a triangle = sum of all sides

84=13x+14x+15x

84=42x

84/42=x

2=x

thus,

13x=13×2

=26 CM

14x=14×2

=28 CM

15x = 15×2

=30 CM

area of a triangle = 1/2×b×h

=1/2×26×30

=390 CM²

Answer 2

Answer:

let a=13x

let b=14x

let c=15x

p=84

a+b+c =perimeter

so,13x + 14x +15x = 84

42x =84

x=84÷42

x=2

now a=13×2=26

b=14×2=28

c=15×2=30

semi perimeter=1÷2 ×84

s=42

area =√S(s-a)(s-b)(s-c)

=√42(42-26)(42-28)(42-39)

=√42×16×14×12

=√14×3×2×2×2×2×14×2×2×3

=14×3×2×2×2

a =984 cm

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