CBSE Notes, Lectures

CBSE - Mathematics - Areas of Parallelograms and Triangles

Areas of Parallelograms and Triangles

NCERT Exercise Exercise 9.3

 In Fig.9.28, AP || BQ || CR. Prove that ar(AQC) = ar(PBR).

In Fig.9.28, AP || BQ || CR. Prove that ar(AQC) = ar(PBR).

Answer

 

Given,

AP || BQ || CR

To Prove,

ar(AQC) = ar(PBR)

Proof:

ar(△AQB) = ar(△PBQ) --- (i) (On the same base BQ and between the same parallels AP and BQ.)

also,

ar(△BQC) = ar(△BQR) --- (ii) (On the same base BQ and between the same parallels BQ and CR.)

Adding (i) and (ii),
ar(△AQB) + ar(△BQC) = ar(△PBQ) + ar(△BQR) 

⇒ ar(△ AQC) = ar(△ PBR)

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