Ответ:

  1. \(c=\sqrt{a^2+b^2}=\sqrt{5^2+7^2}=\sqrt{25+49}=\sqrt{74}\approx8.60\).

  2. \(c=\sqrt{a^2+b^2}=\sqrt{3^2+11^2}=\sqrt{9+121}=\sqrt{130}\approx11.40\).

Ответ: 1) 8,60; 2) 11,40.