Functionality of the app:Makes a toast displying whether the input number is a rectangular or a triangular (or both) number.

The numbers that can be arranged to form a rectangle are called Rectangular Numbers (also known as Pronic numbers). The first few rectangular numbers are: 0, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462 . . . .

Triangular numbers are a pattern of numbers that form equilateral triangles. The formula for calculating the nth triangular number is: T = (n)(n + 1) / 2.