Odpowiedź :
[tex]a_1 = 6\\r = 2\\d = ?[/tex]
[tex]a = 6\\b = 6+2 = 8\\c = 8+2 = 10\\\\d = \sqrt{a^{2} + b^{2} + c^{2}}\\\\d = \sqrt{6^{2} + 8^{2} + 10^{2}}\\\\d = \sqrt{36+64+100}\\\\d = \sqrt{200}\\\\d = \sqrt{100\cdot2}}\\\\\boxed{d = 10\sqrt{2}}[/tex]