Find the lengths of the sides of a triangle

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Discussion Overview

The discussion revolves around determining the lengths of the sides of a triangle given the lengths of its altitudes, specifically 14, 22, and 28. The scope appears to be mathematical reasoning related to triangle properties.

Discussion Character

  • Mathematical reasoning

Main Points Raised

  • One participant presents the problem of finding the side lengths of a triangle based on the given altitudes.
  • Another participant repeats the same problem statement without additional context or modifications.
  • A third participant offers a positive acknowledgment of the initial post, but does not contribute further to the mathematical discussion.

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The discussion does not appear to reach any conclusions or consensus, as the posts primarily consist of repeated problem statements and a single acknowledgment.

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The discussion lacks detailed exploration of the mathematical methods or reasoning required to solve the problem, and no assumptions or definitions are clarified.

Who May Find This Useful

Readers interested in triangle properties, altitude relationships, and mathematical problem-solving may find this discussion relevant.

anemone
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Find the lengths of the sides of a triangle with 14, 22 and 28 as the lengths of its altitude.
 
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anemone said:
Find the lengths of the sides of a triangle with 14, 22 and 28 as the lengths of its altitude.

let the lengths opposite to altitudes of lengths 14,22,28 be x,y,z
then 2 times area
$14x = 22 y = 28 z$
or $x:: y:: z = \frac{1}{14}::\frac{1}{22}:: \frac{1}{28} = 44::28:: 22$(note all kept even to avoid fraction in computation )
so let x= 44t, y = 28t, z = 22t
area = $\dfrac{14x}{2}= 7x = 7 * 44 t = 308t$
using heros formula ( we get $s= \frac{44+28+22}{2}=47$)
$area = \sqrt{47*(47-44)*(47-28)*(47-22)}t^2 = \sqrt{47* 3 * 19* 25}t^2$
or $area = 5\sqrt{47*57}= 5\sqrt{2679}t^2$
so $308t = 5 \sqrt{2679}t^2$
or $t=\frac{308}{5\sqrt{2679}}$
so the sides are
$44t,28t,22t$ where t is as above
 
Last edited:
kaliprasad said:
let the lengths opposite to altitudes of lengths 14,22,28 be x,y,z
then 2 times area
$14x = 22 y = 28 z$
or $x:: y:: z = \frac{1}{14}::\frac{1}{22}:: \frac{1}{28} = 44::28:: 22$(note all kept even to avoid fraction in computation )
so let x= 44t, y = 28t, z = 22t
area = $\dfrac{14x}{2}= 7x = 7 * 44 t = 308t$
using heros formula ( we get $s= \frac{44+28+22}{2}=47$)
$area = \sqrt{47*(47-44)*(47-28)*(47-22)}t^2 = \sqrt{47* 3 * 19* 25}t^2$
or $area = 5\sqrt{47*57}= 5\sqrt{2679}t^2$
so $308t = 5 \sqrt{2679}t^2$
or $t=\frac{308}{5\sqrt{2679}}$
so the sides are
$44t,28t,22t$ where t is as above

Well done, kaliprasad!
 
a = 52.3657142876
b = 33.3236363648
c = 26.1828571438

From Wikipedia:
"Next, denoting the altitudes from sides a, b, and c respectively as ha, hb, and hc, and denoting the semi-sum of the reciprocals of the altitudes as H = (h_a^{-1} + h_b^{-1} + h_c^{-1})/2 we have[11]
A^{-1} = 4 \sqrt{H(H-h_a^{-1})(H-h_b^{-1})(H-h_c^{-1})}."
 
Last edited by a moderator:

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