# How to use Cases to extract sublists [closed]

I have the following values obtained from a table:

aa =
{{13, 7, True,
{{273.055, 414.11}, {257.245, 418.458}, {253.813, 391.}, {261.5, 391.}}},
{62, 4, True,
{{280.225, 468.254}, {279.037, 456.367}, {288.92, 447.472}, {312.404, 455.601},
{310.811, 463.884}}},
{200, 10, True,
{{248.093, 456.364}, {222.27, 447.757}, {210.584, 425.845}, {210.352, 422.125},
{224.754, 418.261}, {232.288, 416.826}, {234.489, 417.364}, {249.333, 424.079},
{251.248, 446.1}, {249.51, 453.683}, {248.405, 456.043}}},
{29, 6, True,
{{206.5, 420.244}, {202.047, 420.141}, {191.868, 389.605}, {206.5, 393.786}}}}

Now, I want to extract those points from the values. So that the values will be:

bb =
{{{273.055, 414.11}, {257.245, 418.458}, {253.813, 391.}, {261.5, 391.}},
{{280.225, 468.254}, {279.037, 456.367}, {288.92, 447.472}, {312.404, 455.601},
{310.811, 463.884}},
{{248.093, 456.364}, {222.27, 447.757}, {210.584, 425.845}, {210.352, 422.125},
{224.754, 418.261}, {232.288, 416.826}, {234.489, 417.364}, {249.333, 424.079},
{251.248, 446.1}, {249.51, 453.683}, {248.405, 456.043}},
{{206.5, 420.244}, {202.047, 420.141}, {191.868, 389.605}, {206.5, 393.786}}}

How can I do it?

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