Question

Help please ...a square card has an area of 15 in.^2 what is the approximate side length of the card

Answer 1

Area = side length²
Because it's a square, all of the side lengths are equal.
15 = s²
s = √(15)
s = √(15) inches

Hope this helps!

Answer 2

$x-the\ length\ of\ the\ side\ a\ square\ card\\\\A_{\fbox{}}=x^2;\ A_{\fbox{}}=15\ in^2\\\\therefore:x^2=15\ in^2\\\\x=\sqrt{15}\ in\\\\\boxed{x\approx3.87\ in}$