Respuesta :

Answer:

The ratio of the radius of the smaller watch face to the radius of the larger watch face is 4:5.

Step-by-step explanation:

Let the Area of smaller watch face be [tex]A_1[/tex]

Also Let the Area of Larger watch face be [tex]A_2[/tex]

Also Let the radius of smaller watch face be [tex]r_1[/tex]

Also Let the radius of Larger watch face be [tex]r_2[/tex]

Now given:

[tex]\frac{A_1}{A_2} =\frac{16}{25}[/tex]

We need to find the ratio of the radius of the smaller watch face to the radius of the larger watch face.

Solution:

Since the watch face is in circular form.

Then we can say that;

Area of the circle is equal 'π' times square of the radius 'r'.

framing in equation form we get;

[tex]A_1 = \pi {r_1}^2[/tex]

[tex]A_2 = \pi {r_2}^2[/tex]

So we get;

[tex]\frac{A_1}{A_2}= \frac{\pi {r_1}^2}{\pi {r_2}^2}[/tex]

Substituting the value we get;

[tex]\frac{16}{25}= \frac{\pi {r_1}^2}{\pi {r_2}^2}[/tex]

Now 'π' from numerator and denominator gets cancelled.

[tex]\frac{16}{25}= \frac{{r_1}^2}{{r_2}^2}[/tex]

Now Taking square roots on both side we get;

[tex]\sqrt{\frac{16}{25}}= \sqrt{\frac{{r_1}^2}{{r_2}^2}}\\\\\frac{4}{5}= \frac{r_1}{r_2}[/tex]

Hence the ratio of the radius of the smaller watch face to the radius of the larger watch face is 4:5.