the sides of a triangle are in the ratio 5 : 12 : 13 and its perimeter is 240 m , its area is ?
"5 x + 12 x + 13 x = 240 = > x = 8 a = 40 , b = 96 , c = 104 s = ( 40 + 96 + 104 ) / 2 = 120 answer : e"
multiply(240, divide(240, add(add(5, 12), 13)))