Question

Find the area of the shaded region. Use 3.14 for π as necessary.

A. 17.1 cm²
B. 34.2 cm²
C. 18.2 cm²
D. 28.5 cm²

Answer 1

34.24 cm²

Explanation:

You first need to find the area of the circle.

4 is radius. r*r*3.14=50.24

Now the triangle is 4*4=16.

50.24-16= 34.24

Answer 2

B.

Explanation:

The area of the shaded region will be the area of the circle minus the area of the triangle inside the circle. Then:

The circle has radius 4 cm (distance from the center to the edge of the circle), so the area of the circle is

`A=\pi r^2 = 3.14(4cm)^2 = 3.14(16cm^2) = 50.24 cm^2.`

Now, the area of the triangle is

`A_2 = (b*h)/(2)`.

The base of the triangle is the diameter of the circle (as you can see in the image) and the height is the radius of the circle. Then the are of the triangle is

`A_2 = (8*4)/(2) = (32)/(2) = 16cm^2`.

Finally, the shaded area is
`A-A_2 = 50.24-16 = 34.24 cm^2`.