9. The sum of two sides must be greater than the third side. It can't be 5 because \(5+5=10
ot>12\). It can't be 7 because \(5+7=12
ot>12\). It can't be 17 because \(5+12=17
ot>17\). So it's 12.
10. a. Turk, McAllister b. Market, Mission, Howard c. not sure about this one