Q9 of 27 Page 228

From a piece of cardboard, in the shape of a trapezium ABCD, and AB||CD and ∠BCD = 900, quarter circle is removed. Given AB = BC = 3.5cm and DE = 2cm. Calculate the area of the remaining piece of the cardboard. (Take to be)

AB = BC = 3.5 cm and DE = 2cm


⇒ DC = DE + EC = 2 + 3.5 = 5.5 cm


As we know that,



Height of trapezium here, BC = 3.5 cm





⇒ AT = 15.75 sq.cm


Now, area of quarter circle = AQ




⇒ AQ = 9.625 sq.cm


Required area = AT – AQ


⇒ Req. area = 15.75 – 9.625 = 6.125 sq.cm


∴ Area of remaining piece of cardboard is 6.125 sq.cm


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