Answer:
Step-by-step explanation:
step 1
Find the area of the plate
The area of a circle is given by the formula
we have
---> the radius is half the diameter
substitute
step 2
Find the area of the square napkin folded (is a half of the area of the square napkin)
we know that
The diagonal of the square is the same that the diameter of the plate
Applying Pythagorean theorem
where
b is the length side of the square
we have
substitute
solve for b^2
-----> is the area of the square
Divide by 2
step 3
Find the area of the space on the plate that is NOT covered by the napkin
we know that
The area of the space on the plate that is NOT covered by the napkin, is equal to subtract the area of the square napkin folded (is a half of the area of the square napkin) from the area of the plate
so
simplify