The amazon river is probably a trellis because it has 2 types of alternating soft and hard rocks. A trellis drainage is the rectangular drainage pattern created if rivers flow through alternating bands of hard and soft rocks.
trellis
It is Dendritic
Dendrtitic river system has a tree like pattern (more common) and trellis river system has a rectangular pattern throughout
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It is Dendritic
The nile is trellis
I would say Trellis because it doesn't look dendritic, but I can't be sure.
The st. Lawrence river is dendritic drainage.
i'm not sure. I think it's a dendritic pattern
both
I don't know about 'treillis' rivers, but the Loire river seems to me to be dendritic (in the sense of arborescent)
trellis as the tributaries meet at approximately right angles
The Mississippi river is a dedentric drainage