Answer :

To find the side of a square given its diagonal, we can use the relationship between the side length and the diagonal of a square.

1. Identify the relationship: In a square, the diagonal divides it into two right-angled triangles. Hence, the Pythagorean theorem applies. The relationship between the side [tex]\( s \)[/tex] of the square and the diagonal [tex]\( d \)[/tex] is given by:
[tex]\[ d = s\sqrt{2} \][/tex]

2. Isolate s: Solving for the side length [tex]\( s \)[/tex], we get:
[tex]\[ s = \frac{d}{\sqrt{2}} \][/tex]

3. Substitute the given diagonal: The given diagonal [tex]\( d = 12\sqrt{10} \)[/tex] feet.

4. Calculate the side length:
[tex]\[ s = \frac{12\sqrt{10}}{\sqrt{2}} \][/tex]

5. Simplify the expression:
[tex]\[ \frac{12\sqrt{10}}{\sqrt{2}} = 12 \times \frac{\sqrt{10}}{\sqrt{2}} = 12 \times \sqrt{\frac{10}{2}} = 12 \times \sqrt{5} \][/tex]
[tex]\[ s = 12 \times \sqrt{5} \][/tex]

6. Evaluate the numerical value: The value of [tex]\( 12\sqrt{5} \)[/tex]:

Based on the given data and through the steps we’ve taken, the calculation gives us:
[tex]\[ s \approx 26.8328 \text{ feet} \][/tex]

So, the side length of the square is approximately [tex]\( 26.8328 \)[/tex] feet.