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Circles I and II are formed from the given quadrants,with centers A and B.
ΔABC is equilateral.
area(ABC)=√3/4*100=25√3
Now let's take a closer look at one circle...say circle I.
AO=BO=AB=10cm
Since both the circles are equal their sectors will also be equal.
angle OAB=60°
Area of sector enclosed by AOB= Π*AB*AB*(60°/360°)
= Î *100/6
Area of ΔABO=25√3
Area of shaded sector enclosed by OB=(Π*100/6)-(25√3)
Area of total shaded region=(25√3)+2{(Π*100/6)-(25√3)
=(Π*100/3)-25√3
=61.4 sq.cm.(approx.)