Question

Which represents a side length of a square that has an area of 450 square inches?

Answer 1

The formula of an area of a square:

$A=a^2$

a - a side

We have $A=450\ in^2$

substitute:

$a^2=450\to a=\sqrt{450}\\\\a=\sqrt{225\cdot2}\\\\a=\sqrt{225}\cdot\sqrt2\\\\\boxed{a=15\sqrt2\ in}$

Used:

$\sqrt{a\cdot b}=\sqrt{a}\cdot\sqrt{b}$