## anonymous one year ago The triangle in the diagram represents a mold that Anna uses to shape dough before baking. Anna also has a circular mold whose rim just fits inside the rim of the triangular mold. What is the radius of the circular mold?

1. anonymous

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2. theEric

Hi! Do you have a formula for this?

3. theEric

I found one at http://www.efunda.com/math/areas/CircleInscribeTriangleGen.cfm That should help! :)

4. anonymous

@theEric it still confuses me a bit can you explain it?

5. theEric

Okay! You need to find $$k$$ to fit into the equation. $k=\frac12(a+b+c)$where $$a$$, $$b$$, and $$c$$ are the lengths of the sides of your triangle.

6. theEric

Then you use those sides and $$k$$ again in the expression $\frac{\sqrt{k(k-a)(k-b)(k-c)\ }}{k}$ The value of that expression IS the radius.