the complete question in the attached figure
we know that
[area of a circle]=pi*r²
for r=1 unit
[area of a circle]=pi*1²---------> pi units²
if the area a full circle of 360°--------------> is pi
the area of sector 88°------------------------> X
X=88*pi/360--------> 0.77 units²
the answer is
the area of sector AOB is 0.77 units²
