What is the area of the sector if a circle has a central angle measurement of pi/6 and a radius of 4 cm?

M∠cbd=4x+52∘ m∠abc=8x−10∘\qquad m \angle abc = 8x - 10^\circm∠abc=8x−10∘ find m∠cbdm\angle cbdm∠cbd:

Mario and luigi were printing calendars mario used 2 1/2 ink cartridges while luigi used 1 3/4 ink cartridges .how many more ink cartridges did mario use than luigi

Me because i don't understand how to do it.: )