Draw an equilateral $\Delta XYZ$ with perimeter $21\,cm$. Write the steps of construction.

(N/A) $1$. Calculate the side length of the equilateral triangle: Since the perimeter is $21\,cm$,each side length $= 21\,cm / 3 = 7\,cm$.
$2$. Draw a line segment $XY = 7\,cm$ using a ruler.
$3$. Set the compass width to $7\,cm$.
$4$. Place the compass point at $X$ and draw an arc above the line $XY$.
$5$. Place the compass point at $Y$ and draw another arc intersecting the previous arc at point $Z$.
$6$. Join $XZ$ and $YZ$ using a ruler.
$7$. The resulting $\Delta XYZ$ is the required equilateral triangle with each side $7\,cm$ and perimeter $21\,cm$.