Explanation:
here's your solution
==> ratio of sides of traingle are given = 7:9:12
==> perimeter of traingle = 56
==> let the ratio be X
==> now , 7x + 9x + 12x = 56
==> 28x = 56
==> x = 56/28
==> x = 2
... length of sides = 7x = 14
.....9x = 18
12x = 24
. length of. sides = 14 ,18 ,.24