Some one gave me this statement, but what’s the reason?

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'

I'm marking the brainliest and it's 15 points

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.