The sides of a triangle having area $7776 \ cm^2$ are in the ratio $3:4:5$. The perimeter of the triangle is ........ $cm$.

The minute-hand of a clock is $14 \, cm$ long. The area covered by the minute hand in $30 \, min$ is.............$cm^2$

$A$ tank is $25 \ m$ long,$12 \ m$ wide and $6 \ m$ deep. The cost of plastering its walls and bottom at $75 \ paise/m^2$ is (in $Rs.$)

The perimeter of an equilateral triangle is $72 \sqrt{3} \text{ cm}$. Find its height in meters.

$A$ steel sphere of radius $4 \, cm$ is drawn into a wire of diameter $4 \, mm$. Find the length of the wire in $mm$.

$ABC$ is a triangle. $AB = 5 \text{ cm}$,$AC = \sqrt{41} \text{ cm}$,and $BC = 8 \text{ cm}$. $AD$ is perpendicular to $BC$. What is the area (in $\text{cm}^2$) of triangle $ABD$?