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
