Driver code
public static void Main ( ) { int num = 55 ; if ( isTriangular ( num ) ) Console . WriteLine ( " The ▁ number ▁ is ▁ a ▁ " + " triangular ▁ number " ) ; else Console . WriteLine ( " The ▁ number ▁ is ▁ NOT ▁ " + " a ▁ triangular ▁ number " ) ; } }