Question

Help plz what is the approximate area of the shaded region?

A. 21.5 square centimeters
B. 100 square centimeters
C. 178.5 square centimeters
D.78.5 square centimeters

Answer 1

See below

Explanation:

There aren't any shaded area given and no diagram. So, the answer choices won't hold. I will attach one figure that has shaded region and show general way of finding area.

Here,

We have a square

Also, we have a circle

The area of shaded region is:

Area of Shaded = Area of Square - Area of Circle

Area of Square = length * length

Area of Circle =
`\pi r^2`

Now,

Area of square with lengths 20 each, is:

Area of Square = 20*20 = 400

Also,

Area of circle with diameter given 20, means radius is 20/2 = 10, so

Area of Circle =
`\pi (10)^2 = 100\pi`

Area of Shaded =
`400-100\pi=85.84` square centimeters

Answer 2

Option A

Explanation:

As ler the comment above, the square has sides of 10cm and circle inside it has a diameter of 10cm, to mean the radius of the circle is 5cm

The area of square is given by d*d

The area of circle is given by
`\pi*r^(2)`To get area of shaded part where we have a square of 10 cm and inside square is a circle of 10 cm diameter, then the shaded area is

Area of square minus circle

Area of square is 10*10=100

Area of circle is 3.14*5*5=78.5

Shaded area is 100-78.5=21.5 square centimeters