Question:
A square board has an area of 144 sq units. How long is each side of the board?
(a) 11 units
(b) 12 units
(c) 13 units
(d) 14 units
Solution:
(b) Given, area of square board $=144 \mathrm{sq}$ units
$\therefore$ $(\text { Side })^{2}=144$ $\left[\because\right.$ area of square $\left.=(\text { side })^{2}\right]$
$\Rightarrow$ $(\text { Side })^{2}=(12)^{2}$
$\Rightarrow$ Side $=12$ units
Hence, the length of each side of the board is 12 units.