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The Given Figure Shows a Rectangle Abdc and a Parallelogram Abef; Drawn on Opposite Sides of Ab. Prove That: Quadrilateral Cdef is a Parallelogram Area of Quad. Cdef = Area of Rect. Abdc

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Question

The given figure shows a rectangle ABDC and a parallelogram ABEF; drawn on opposite sides of AB.
Prove that: 
(i) Quadrilateral CDEF is a parallelogram;
(ii) Area of the quad. CDEF
= Area of rect. ABDC + Area of // gm. ABEF.

Sum
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Solution

After drawing the opposite sides of AB, we get

Since from the figure, we get CD//FE, therefore, FC must parallel to DE. Therefore it is proved that the quadrilateral CDEF is a parallelogram.

The area of the parallelogram on the same base and between the same parallel lines is always equal and the area of the parallelogram is equal to the area of a rectangle on the same base and of the same altitude i.e, between the same parallel lines. 

So Area of CDEF= Area of ABDC + Area of ABEF 
Hence Proved

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Figures Between the Same Parallels
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Chapter 16: Area Theorems [Proof and Use] - Exercise 16 (A) [Page 196]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 16 Area Theorems [Proof and Use]
Exercise 16 (A) | Q 2 | Page 196

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