Answer:
21.3 unit
Step-by-step explanation:
[tex]side CB=\sqrt{(7^{2})+(2^{2})} =\sqrt{53}\\side CA=\sqrt{(5)^{2}+(2^{2})} =\sqrt{29} \\side AB=\sqrt{(5^{2} )+(7^{2} )} =\sqrt{74}[/tex]
[tex]Perimeter=\sqrt{53} +\sqrt{29} + \sqrt{74} =21.2676[/tex] unit