The pentagons are similar because all the sides of the big one are exactly double the lengths of the little one and all the angles are the same.
Yea, the triangles are too.
The two little triangles are congruent but I would think congruence is just a very specific version of similar.
In the same way the a square is a special case of a rectangle.
For the triangle ones you're right melody
if you take a look, you'll notice that the smaller triangles are exactly the same size (by the slope, 1/4)
take that slope on the big one, and that big triangle is twice the size of a little triangle, in other words, two small triangles combined
congruent and similar melody are basically the same thing
these triangles have the same shape, and same orientation, pretty much same everything but different size, but the size are, how should I say it, equivalent? To scale?
Either way, you're right on the triangle part, Melody