The dimensions of a rectangular acrylic sheet = 36 cm × 25 cm.
∴ Its area = l × b
= 36 × 25 = 900 sq.cm
The diameter of a circular button = 3.5 cm
radius = r = d/2 = 3.5/2 = 1.75 cm.
∴ Area of each button = πr2
= 22/7 × (1.75)2
= 22/7 × 1.75 × 1.75
= 9.625 sq.cm.
The area of 56 such buttons = 56 × 9.625 = 539 sq.cm.
∴ The area of remaining sheet
= Area of a rectangular sheet – Area of 56 buttons
= 900 – 539
= 361 sq.cm
