A point in the figure is selected at random. Find the probability that the point will be in the shaded region.

A. about 25%
B. about 60%
C. about 50%
D. about 75%

A point in the figure is selected at random Find the probability that the point will be in the shaded region A about 25 B about 60 C about 50 D about 75 class=

Respuesta :

Area of the figure:
Af = a² + 2 a²/4 π = 2.57 a²
Area of the shaded region:
As = 2 a²/4 π = 1.57 a²
x = (1.57 · 100) / 2.57 = 61 % ≈ 60 %
Answer: B) about 60 %

Answer:

B. about 60%

Step-by-step explanation:

Let us assume that the radius of the semi-circle is d units.

So the area of the semi-circle will be,

[tex]=\dfrac{\pi d^2}{2}[/tex]

In total there are 4 semi circles, so the net area will be,

[tex]=4\times \dfrac{\pi d^2}{2}[/tex]

[tex]=2\pi d^2[/tex]

The side length of the square is twice the radius of the semi circle. So the side length of the square is 2d units.

Area of the square is,

[tex]=(2d)^2\\\\=4d^2[/tex]

The total area will be,

[tex]=2\pi d^2+4d^2[/tex]

So that the random point will be in the shaded region is,

[tex]=\dfrac{\text{Area of semi circles}}{\text{Area of square}}[/tex]

[tex]=\dfrac{2\pi d^2}{2\pi d^2+4d^2}[/tex]

[tex]=\dfrac{2\pi}{2\pi+4}[/tex]

[tex]=0.6[/tex]

[tex]=60\%[/tex]