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Using the information in the following figure, find the area of the trapezium.

Using the information in the following figure, find the area of the trapezium. Area and Perimeter of Plane Figures, Concise Mathematics Solutions ICSE Class 9.

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Answer

Draw a perpendicular line CP on AB, such that CP = 9 m and AP = 23 m.

Let PB = a m

Using the information in the following figure, find the area of the trapezium. Area and Perimeter of Plane Figures, Concise Mathematics Solutions ICSE Class 9.

In Δ CPB, by using the Pythagoras theorem,

Base2 + Height2 = Hypotenuse2

⇒ a2 + (9)2 = (15)2

⇒ a2 + 81 = 225

⇒ a2 = 225 - 81

⇒ a2 = 144

⇒ a2 = 144

⇒ a = 144\sqrt{144}

⇒ a = 12 m

So, AB = AP + PB = 23 + 12 = 35 m

Area of trapezium = 12\dfrac{1}{2} (sum of parallel sides) x height

= 12\dfrac{1}{2} (23 + 35) x 9

= 12\dfrac{1}{2} x 58 x 9

= 29 x 9

= 261 m2

Hence, the area of the trapezium is 261 m2.

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