2005 Canadian MO Problems/Problem 4
Let the sides of triangle be , , and . Thus , and . We plug these in:
Now Heron's formula states that . Thus,
^hahahaha... you can probably use Ravi Sub. to finish the above.
Use the formula to get . Then use the extended sine law to get something in terms of sines, and use AM-GM and Jensen's to finish. (Jensen's is used for .