There would be 10 yellow shirts and 19 white shirts...hope its right...
Area of the sector = 90/360 ×πr^2
=1/4 ×3.142×6×6
=1/4×113.112
=28.278kilometers square
Approximately 28kilometers square
5.26 Orr 5.27 (if you round up) :)
*5 and above give it a shove, 4 below let it go* lol