Răspuns:
[tex]AC=\sqrt{1+16}=\sqrt{17} \\BC=\sqrt{16+9}=5\\ AB=4\\p=\frac{5+4+\sqrt{17} }{2} =\frac{9+\sqrt{17} }{2} \\A=\sqrt{p(p-a)(p-b)(p-c)}=\sqrt{\frac{9+\sqrt{17} }{2}*\frac{9-\sqrt{17} }{2} * \frac{\sqrt{17}-1 }{2}*\frac{\sqrt{17}+1 }{2} } =\sqrt{\frac{(81-17)(17-1)}{16} } =\frac{8*4}{4} =8[/tex]
