Can you me put this number in standard form that in the red circle

Let's look at each number.
It goes from greatest to least, following 6 trillion.
6,000,000,000
Now, we need a number to fill the bolded 0.
Three hundred million will fill the bolded 0.
6,300,000,000
This is all you have. We need a number to fill the bolded 0.
Forty million will replace it.
6,340,000,000
Now, we need a number to fill the bolded number.
Two million will replace it.
6,342,000,000
We have nothing left. So, the standard form of the expanded form is 6,342,000,000.

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)