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

Aabout 25%
Babout 60%
Cabout 50%
Dabout 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=

Verified Answer :

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,

\(=\dfrac{\pi d^2}{2}\)

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

\(=4\times \dfrac{\pi d^2}{2}\)

\(=2\pi d^2\)

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,

\(=(2d)^2\\\\=4d^2\)

The total area will be,

\(=2\pi d^2+4d^2\)

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

\(=\dfrac{\text{Area of semi circles}}{\text{Area of square}}\)

\(=\dfrac{2\pi d^2}{2\pi d^2+4d^2}\)

\(=\dfrac{2\pi}{2\pi+4}\)

\(=0.6\)

\(=60\%\)