Herons Formula (1 Viewer)

[loser101]

Find area of ANY triangle given the 3 sides

[SIZE=-0]<center>A = sqrt [ s * (s - a) * (s - b) * (s - c) ]
Where s = (1 / 2)(a + b + c).

Proof: Really quite lovely
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</dd></dl> by the law of cosines. From this we get the algebraic statement:
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.</dd></dl> The altitude of the triangle on base a has length bsin(C), and it follows
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[wogblogger]

omg
this was the only formula i knew untill year 11
i failed all maths untill year 11 but i never forgot this formula

 

[buchanan]

Here's Wildberger's youtube on it. He uses rational trig.

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( http://www.youtube.com/watch?v=hooQuHLS-kk )

 

[Affinity]

Yeah, his pet topic