What does rēctangulus mean in Latin?

rēctangulus, a adjective, means “rectangular”.

How do you pronounce rēctangulus?

In classical Latin, [reːkˈtaŋ.ɡʊ.ɫʊs]; in ecclesiastical (church) Latin, [rekˈtaŋ.ɡu.lus].

Proto-Indo-European *h₃reǵ- → Proto-Indo-European *h₃reǵtós → Proto-Italic *rektos → Latin rēctangulus.

adjectivefirst/second-declension adjective

rēctangulus (feminine rēctangula, neuter rēctangulum)

Classical[reːkˈtaŋ.ɡʊ.ɫʊs]Ecclesiastical[rekˈtaŋ.ɡu.lus]

singular
form	masculine	feminine	neuter
nominative	rēctangulus	rēctangula	rēctangulum
genitive	rēctangulī	rēctangulae	rēctangulī
dative	rēctangulō	rēctangulae	rēctangulō
accusative	rēctangulum	rēctangulam	rēctangulum
ablative	rēctangulō	rēctangulā	rēctangulō
vocative	rēctangule	rēctangula	rēctangulum

plural
form	masculine	feminine	neuter
nominative	rēctangulī	rēctangulae	rēctangula
genitive	rēctangulōrum	rēctangulārum	rēctangulōrum
dative	rēctangulīs	rēctangulīs	rēctangulīs
accusative	rēctangulōs	rēctangulās	rēctangula
ablative	rēctangulīs	rēctangulīs	rēctangulīs
vocative	rēctangulī	rēctangulae	rēctangula

Proto-Indo-European *h₂eng- Proto-Indo-European *h₂engulos Proto-Italic *angulos Latin angulus Latin rēctangulus From rectus + angulus.