area of rectangle = 60 x 20 = 1200
area of circle = πr^2 = π * 10^2 = 100π
3 circles = 100π x 3 = 300π
shaded area = 1200 - 300π = 300(4 -π)
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if you want to apply π = 3.14 then
shaded area = 1200 - 300π = 300(4 -3.14) = 257.52
