I want round to round to the nearest 10th instead of the nearest integer... Any ideas?

public class Triangle 
{
    private final int leg;
    private final double hypotenuse;
 
    public Triangle( int l )
    {
        leg = l;
        hypotenuse = leg*Math.sqrt( 2.0 );
    }    
 
    public int getLeg()
    {
        return leg;
    }
 
    public double getHypotenuse()
    {
        return hypotenuse;
    }
 
    @Override
    public String toString()
    {
        return String.format( "Triangle(%d)", leg );
    }
}

Triangle(5)
Leg: 5
Hypotenuse: 7.0 (this should be 7.1)