Answer:
P = 90 cm
Step-by-step explanation:
Let the sides of a triangle are 3x,5x and 7x.
The difference between the longest side and the shortest side is 24cm i.e.
7x-3x = 24
4x = 24
x = 6
Sides are :
3x = 3(6) = 18 cm
5x = 5(6) = 30 cm
7x = 7(6) = 42 cm
Perimeter = sum of all sides
P = 18+30+42
P= 90 cm
Hence, the perimeter of the triangle is equal to 90 cm.