Both these hymns have gāyatrī chandaḥ in the preamble where it lists ṛṣiḥ, devatā,chandas. But the metre of both these hymns is 4 feet of 8 syllables each, and  Apte`s dictionary lists  gāyatrī metre as 4 feet of 6 syllables each.  Can someone explain this.

 https://stotranidhi.com/en/sri-gayatri-kavacham-in-english/

https://sanskritdocuments.org/doc_devii/indramahaalaxmiikavach.pdf

Thanks,