# Check

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I came up with a cheap formula to solve the surfice of any triangle. Though I'm not sure if it is correct. I wonder if you 1337 guys could check it.*points to sig*

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I checked the formula by using c=5, b=3, a=4, but first, I used the $c^{2}=a^{2}+b^{2}$. The surface area should be 5. Then I put in the variable with the known numbers, using this formula:$S_{triangle}=\frac{c\sqrt{b^2-\left(\frac{b^2-a^2+c^2}{2c}\right)^2}}{2}$. I got a 6 for an answer following my calculation, so the formula would be right, if it have minus 1 like this: $S_{triangle}=\frac{c\sqrt{b^2-\left(\frac{b^2-a^2+c^2}{2c}\right)^2}}{2}-1$. Therefore the answer would be 5, thus the surface area for a triangle with c=5, b=3, a=4.

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Ahem...$S_{triangle}=\frac{3*4}{2}=6$

Don't you just hate it when that happens when doing calculations in your head. ##### Share on other sites

[math']c^{2}=a^{2}+b^{2}[/math]

That is the pythagorean theorem, not area.

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WHOOPS! I mistakely used the pythagorean theorem to find the surface area of a triangle! Stupid me. The formula to find the surface area for a triangle is $A=\frac{1}{2}bh$. Therefore, $\frac{1}{2}4*3$ is 6. So the big crazy formula is correct. ## Create an account

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