In figure, ABCD is a trapezium with AB||DC. AB = 18 cm, DC = 32 cm and distance between AB and DC = 14 cm. If arcs of equal radii 7 cm with centers A, B, C and D have been drawn, then find the area of the shaded region of the figure.


AB = 18 cm, DC = 32 cm


Distance between AB and DC = Height = 14 cm


Now, Area of the trapezium = (1/2) × (Sum of parallel sides) × Height


= (1/2) × (18+32) × 14 = 350cm2


As AB DC, A + D = 180°


and B + C = 180°


Also, radius of each arc = 7 cm


Therefore,


Area of the sector with central angle A = (1/2) × (A/180) × π × r2


Area of the sector with central angle D = (1/2) × (D/180) × π × r2


Area of the sector with central angle B (1/2) × (B/180) × π × r2


Area of the sector with central angle C = (1/2) × (C/180) × π × r2


Total area of the sectors =




= 77 + 77 = 154


Area of shaded region = Area of trapezium – (Total area of sectors)


= 350 – 154 = 196 cm2


Hence, the required area of shaded region is 196 cm2.


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