the perimeter of a rhombus is 260 cm and the height is 10 cm . if one diagnol is 0.25 m, find the length of other diagnol also in metres.

Suppose a be the length of each side of rhombus.
So, its perimeter = 4a = 260 cm
$\Rightarrow a = \frac{260}{4}$ = 65 cm = 0.65 m
Height of rhombus = 10 cm = 0.1 m
So, area of rhombus = base $\times$ height = 0.65 $\times$ 0.1 = 0.0650 ${\mathrm{m}}^2$
Now, length of one diagonal of rhombus = 0.25 m
Suppose length of other diagonal is d
And we know that area of rhombus when length of diagonals are given = $\frac{1}{2}$ (product of length of two diagonals)
So, we have;
$$\begin{gathered} \frac{1}{2}\left(d\times 0.25\right) = 0.065 \\ \Rightarrow d\times 0.25 = 0.065\times 2 \\ \Rightarrow d = \frac{ 0.065\times 2}{0.25} = 0.52 \end{gathered}$$
Therefore, length of other diagonal is 0.52 m.