$(1$ point$)$

The $30-60-90$ right$-$angle triangle has two legs and a hypotenuse.

$BC$ is $=7\mathrm{.}9cm.$

Find the length of $AC$

$cm.$

Find the length of $AB$

$cm.$

Find the value of the area

$c{m}^2.$

Find the value of the perimeter

$cm.$