How many measures will this rhythm be divided into if each measure contains 3 beats?

The gregorian chant was a major cultural milestone in the middle ages. it was one of the first codified forms of music meant to be played as written, where previously it was difficult to mass-produce and disseminate any music. what's more, these chants were also some of the first examples of musical notation: the notes and bars of today's music sheets are a reflection of centuries of evolution beginning with these chants. it became official throughout the entirety of the catholic church, meaning that nearly all of europe followed this musical notation and styling.

The artist above used rapid brushstrokes 

The technique was mural painting and he used either freshly laid or wet lined plaster. he also use water to merge it with the pigment and plaster creating a internal part of the wall