In triangle ABC, if $${{{{\sin }^2}A + {{\sin }^2}B + {{\sin }^2}C} \over {{{\cos }^2}A + {{\cos }^2}B + {{\cos }^2}C}} = 2$$, then the triangle is

Match List-I with List-II and select the correct answer using the code given below the lists

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If $$\sin A = {3 \over 5}$$, where $$450^\circ < A < 540^\circ $$, then $$\cos {A \over 2}$$ is equal to

What is $${1 \over {\sin 10^\circ }} - {{\sqrt 3 } \over {\cos 10^\circ }}$$ equal to?