**Problem of the Week #11**__:__ (Fall, 2014, for the week of 10/27/2014 – 10/31/2014)

A triangle with sides of length *a*, *b*, and *c* is such that (*a* + *b* + *c*)(*a* + *b* - *c*) = 3*ab*. Find the measure of the angle opposite side *c*. Clearly show the mathematical process that you use to __ find__ your solution.

Solutions are due at or before noon, Friday October 31.

**Rules:**

- This contest is open to any students who are registered at Sinclair for the Fall semester of 2014. It is expected that students will
**work alone**on the problems. - Weekly problems will be posted on the board in the Math Help Room Monday mornings. Solutions to a problem will appear there the following week.
- All answers must be substantiated
**by hand**for credit (show all work). Programs written to solve the problem by computer or calculator will not count as sufficient justification. - Submit solutions to Susan Harris in room 01-331. You may slip them under her office door anytime before Friday at noon.
- Names of all students who submit correct solutions on time will be posted by the following week.
- A prize of $50 will be awarded to the student who correctly answers the most problems for the quarter, and a prize of $25 will be awarded to the second place winner.