Mario is constructing a square dart board. It will consist of a smaller square centered in a larger square. The smaller square measures $4$ inches on each side. The ratio of the area of the smaller square to the area of the entire dart board is $\frac 49$. How long is the side of the larger square?

Respuesta :

Answer:

6 inches.

Step-by-step explanation:

Let a represent side length of larger square.

We know that area of square is square of its side length, so area of the larger square will be [tex]a^2[/tex].

The area of smaller square would be [tex]4^2[/tex].

We will use proportions to solve our given problem.

[tex]\frac{\text{Area of smaller square}}{\text{Area of larger square}}=\frac{4}{9}[/tex]

[tex]\frac{4^2}{a^2}=\frac{4}{9}[/tex]

[tex]\frac{16}{a^2}=\frac{4}{9}[/tex]

Cross multiply:

[tex]4*a^2=16*9[/tex]

[tex]\frac{4*a^2}{4}=\frac{16*9}{4}[/tex]

[tex]a^2=36[/tex]

Take square root:

[tex]a=\pm\sqrt{36}[/tex]

[tex]a=\pm 6[/tex]

Since the length cannot be negative, therefore, the side length of larger square is 6 inches.

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