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Show that: A diagonal divides a parallelogram into two triangles of equal area.

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Question

Show that:

A diagonal divides a parallelogram into two triangles of equal area.

Sum
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Solution

Suppose ABCD is a parallelogram    ...(given)

Consider the triangles ABC and ADC:

AB = CD           ......[ABCD is a parallelogram]

AD  = BC        ......[ABCD is a parallelogram]

AC = AC          .....[Common]

By Side- Side -Side criterion of congruence, we have,

ΔABC ≅ ΔADC

Area of congruent triangles are equal.

Therefore, Area of ABC = Area of ADC

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Figures Between the Same Parallels
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Chapter 16: Area Theorems [Proof and Use] - Exercise 16 (B) [Page 201]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 16 Area Theorems [Proof and Use]
Exercise 16 (B) | Q 1.1 | Page 201

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