Name three fractions whose decimal equivalent is 0.40.draw a picture if it you explains

0.40 is actually 2/5.

2/5=4/10=8/20=16/40

How did I create all of these fractions?

Quite simple... I multiplied each fraction by 1... What do you mean?

2/5*2/2=4/10

2/2 is one by the way.

4/10*2/2=8/20.

You get the idea?

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)