Question

the lengths of a triangle whose sides are in the ratio 13:14:15 and it's perimeter is 84 cm. find the area of the triangle.

Answer 1

first find the side
take the sides as 13x,14x,15x
therefore, 13x + 14x + 15x = 84
52x = 84
x = 84-52 = 32
now you have to just find the area

Answer 2

let the three sides be 13x , 14x, 15x
perimeter given = 84
according to the sum,
13x + 14x + 15x =84
x (13 + 14 + 15) = 84
x (42) = 84
42x = 84
x = 84 / 42 = 2/1 = 2
first side = 13 x = 13 * 2 = 26
14x = 14 * 2 = 28 
15x = 15 * 2 =30