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Abcd is Trapezium with Ab // Dc. a Line Parallel to Ac Intersects Ab at Point M and Bc at Point N. Prove That: Area of δ Adm = Area of δ Acn.

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Question

ABCD is a trapezium with AB // DC. A line parallel to AC intersects AB at point M and BC at point N.
Prove that: area of Δ ADM = area of Δ ACN.

Sum
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Solution

Given: ABCD is a trapezium.

AB || CD, MN || AC
Join C and M

We know that the area of triangles on the same base and between the same parallel lines are equal.
So Area of ΔAMD = Area of ΔAMC

Similarly, consider the AMNC quadrilateral where MN || AC.
ΔACM and ΔACN are on the same base and between the same parallel lines. So areas are equal.

So, Area of ΔACM = Area of ΔCAN
From the above two equations, we can say
Area of ΔADM = Area of ΔCAN

Hence Proved.

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Figures Between the Same Parallels
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Chapter 15: Area Theorems [Proof and Use] - Exercise 16 (A) [Page 197]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 15 Area Theorems [Proof and Use]
Exercise 16 (A) | Q 15 | Page 197

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