Решение: a) \(b = \sqrt{c^2 - a^2} = \sqrt{13^2 - 12^2} = 5\); б) \(b = \sqrt{c^2 - a^2} = \sqrt{9^2 - 7^2} = 4\); в) \(b = \frac{c}{2} = \frac{12}{2} = 6\); г) \(b = \sqrt{\frac{c^2}{4} - a^2} = \sqrt{\frac{(2\sqrt{3})^2}{4} - (2\sqrt{3})^2} = \sqrt{0} = 0\); д) \(b = \sqrt{\frac{c^2}{4} - a^2} = \sqrt{\frac{(2\sqrt{10})^2}{4} - (3b)^2} = ...\).