The sides of a triangle measure $12 \ cm$,$35 \ cm$,and $37 \ cm$. Find the area of the triangle. (in $cm^2$)

The ratio of the measures of the sides of a triangle is $3: 4: 6$. If the semiperimeter of the triangle is $39 \, cm$,the measure of the longest side of the triangle is ............ $cm$.

Write True or False and justify your answer.
The area of an equilateral triangle is $20 \sqrt{3} \text{ cm}^2$ whose each side is $8 \text{ cm}$.

The area of an equilateral triangle with side $2 \sqrt{3} \, cm$ is (in $cm^2$):

In a right-angled triangle,the length of the hypotenuse is $29\,cm$ and one of the sides forming the right angle is $21\,cm$. Then,the semi-perimeter of the triangle is ............ $cm$.

$\Delta ABC$ is an isosceles triangle in which $BC = 24 \, cm$ and $AB = AC = 13 \, cm$. Then,the area of $\Delta ABC = \dots \, cm^2$.