Dendropsophus triangulum (common name: triangle treefrog) is a species of frog in the Hylidae family.It is found in the upper Amazon Basin in Bolivia, western Brazil, Colombia, Ecuador, and Peru. Dendropsophus triangulum is widespread but generally uncommon. It is most commonly found around temporary ponds in clearings near forest, but can be also found in forests. Breeding takes place in temporary ponds, where the tadpoles develop.