Question

find the area of triangle whose sides are in the ratio 5 is to 1 is to 13 and it's perimeter is 60 cm

Answer 1

Let ABC be a triangle
then
AB + BC + CA = 60
5x +12x +13x = 60
30x=60
x = 2
AB = 10
BC = 24
CA = 26

Area of triangle = 1/2 x AB x BC
                        = 0.5 x 10 x 24
                           = 120 sq.cm

Answer 2

sum of ratios = 5+1+13 =19
perimeter = 60 cm
Therefore,
1st side  =(5/19)*60   = 15.789 = (approximately) 15.79 cm
2nd side =(1/19)*60   =  3.157  = (approximately)   3.16 cm
3rd side  =(13/19)*60 = 41.052 = (approximately) 41.05 cm