+3 votes
in Class 9 by kratos

Triangles having equal areas and having one side of the triangle equal to corresponding side of the other, have their corresponding altitudes equal. Prove that.

1 Answer

+4 votes
by kratos
 
Best answer

Given : Two triangles ABC and PQR such that (i) ar (∆ABC) = ar(∆PQR) and (ii) AB = PQ.

CN and RT and the altitude corresponding to AB and PQ respectively of the two triangles.

To prove : CR = RT.

Proof: In ∆ABC, CN is the altitude corresponding to the side AB.

ar(∆ABC) = 1/2 AB × CN ....(i)

Similarly, ar(∆PQR) = 1/2 PQ × RT ....(ii)

Since ar(∆ABC) =ar(∆PQR) [Given]

∴ 1/2 AB × CN = 1/2 PQ × RT

Also, AB = PQ [Given]

CN = RT

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