Question

does somebody knows how to do this one?

Answer 1

Explanation:

To find the area subtract the area of the semicircle from the area of the rectangle.

Although the line isn’t there, if you imagine there is one, then you will see that you form a rectangle which is the same line as the semicircle’s diameter.

The area of rectangle is:

⇒
`A = lw`

⇒
`A = (14)(8)`

⇒
`A = 112cm^(2)`

The area of the semicircle;

⇒
`A = (1)/(2)\pi r^(2)`

⇒
`A = (1)/(2)\pi (7)^(2)`

*Note here that the radius is half the diameter, so it is 7cm, not 14cm

⇒
`A = 76.97cm^(2)`

Finally subtract the two areas;

⇒
`A = 112 - 76.97`

⇒
`A = 35.03cm^(2)`