Let ABCD be a trapezium, with parallel sides AB = 25 m, CD = 10 and non- parallel sides BC = 14 m and AD = 13 m. Draw CM perpendicular AB and CE|| AD. For ΔΒCE BC = 14 m CE = AD = 13 m BE = AB - AE = 25 – 10 = 15 m ( ∴ AE = CD = 10 m) Now, Let a = 14 m, b = 13 m and c = 15 m ∴ Semi-perimeter(s) = ( a + b + c)/2 = ( 14 + 13 + 15)/2 = 21 m ∴ Area of △BCE = root under( √s(s - a)(s - b)(s – c)) = root under( √21(21 – 14) (21 - 13)(21 - 15)) = root under( √21 x 7 x 8 x 6) = root under( √3 x 7 x 7x 2 x 2 x 2 x 2 x 3) = 2 X 2 X 3 X 7 = 84 m2 Also, area ( △BCE) = 1/2 x BE x CM ⇒ 84 = 1/2 x 15 x CM ⇒ CM = 2 x 84/15 ⇒ CM = 56/5m Now, area of parallelogram AECD = base x altitude = AE x CM = 10 x 56/5 m2 = 112 m2 ∴ Area of trapezium = area of parallelogram AECD + area of △BCE = 112 + 84 = 196 m2