Question

Calculate the radius and the area of the brick region?

Answer 1

See a solution process below:

Explanation:

The diameter of the shaded area is the same as the height of the rectangular area: 30cm

The relationship between the radius and diameter of a circle is:

`d = 2r` or `r = d/2`

Substituting the diameter gives the radius as:

`r = (30"cm")/2 = 15"cm"`

The RADIUS of the shaded area is: 15cm

The formula for the area of a circle is:

`A_c = pir^2`

Substituting the radius from above and calculating the area gives:

`A_c = pi * (15"cm")^2`

`A_c = pi * 225"cm"^2`

`A_c = 225pi"cm"^2`

Or, using 3.14 to approximate `pi`:

`A_c ~= 225 * 3.14"cm"^2`

`A_c ~= 706.5"cm"^2`

The AREA of the shaded area is approximately 706.5 square centimeters