Chu vi căn phòng:
\(2\left(\sqrt{28+10\sqrt{3}}+\sqrt{28-10\sqrt{3}}\right)=2\left(\sqrt{\left(5+\sqrt{3}\right)^2}+\sqrt{\left(5-\sqrt{3}\right)^2}\right)\)
\(=2\left(5+\sqrt{3}+5-\sqrt{3}\right)=2.10=20\left(m\right)\)
Diện tích căn phòng:
\(S=\sqrt{28+10\sqrt{3}}.\sqrt{28-10\sqrt{3}}=\sqrt{\left(28+10\sqrt{3}\right)\left(28-10\sqrt{3}\right)}=\sqrt{28^2-\left(10\sqrt{3}\right)^2}\)
\(=\sqrt{484}=22\left(m^2\right)\)
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