Please Could someone tell me what:

Question

1. A square number is
2. A cube number is
3. A triangle number is

Thank you

Square numbers are the result of squaring an integer (IxI)

Cube numbers are the result of the cube of an integer (IxIxI)

A triangular number is a number such that the shape of an equilateral triangle can be formed by the number of dots.
Difficult to draw here, but the first three are 1,3,6 as

.

.
.
.

.
.
. .
.
.

Is this OK? Next one is?

Oops the dots didn't work.

I usually illustrate triangular numbers with the example of setting up a triangle of billiard balls
with 1 row you have 1 ball
with 2 rows you have 3 balls
with 3 rows you have 6 balls
with 4 rows you have 10 balls
etc.