public class TriangleUtilities {

    public static String getRow(int numberOfStars) {
        StringBuilder sb = new StringBuilder();
        //String str = "";
        for (int i =0; i < numberOfStars; i++){
        //str += "*";
        sb = sb.append("*");
        }
        //return str;
        return sb.toString();
    }
    
    public static String getTriangle(int numberOfRows) {
        StringBuilder sb = new StringBuilder();
        
        for (int i = 0; i < numberOfRows; i++) {
        
            for (int j = 0; j <= i; j++) 
            {
                //if (j<i)
                
                sb = sb.append("*");
            }
              sb.append("\n");
        }
      
        return sb.toString();
    }


    public static String getSmallTriangle() {
        StringBuilder sb = new StringBuilder();
        
        for (int i = 0; i < 4; i++) {
        
            for (int j = 0; j <= i; j++) 
            {
                //if (j<i)
                
                sb.append("*");
            }
            sb.append("\n");
        }
        
        
        System.out.print(sb);
        return sb.toString(); 
    }

    public static String getLargeTriangle() {
    StringBuilder sb = new StringBuilder();
        
        for (int i = 0; i < 9; i++) {
        
            for (int j = 0; j <= i; j++) 
            {
                //if (j<i)
                
                sb.append("*");
            }
            sb.append("\n");
        }
        
        
        System.out.print(sb);
        return sb.toString(); 
    }
    
}