Question

I need help on this question please and explanation

Answer 1

453.73
`km^(2)` (the last option, in red)

Explanation:

The formula for finding the area of a semi circle is half the formula for finding the area of a whole circle ( since semi is half a circle). The formula is:

`(\pi r^(2) )/(2)` where r is the radius.

Since the diameter is given, we have to first find the radius of the circle.

Radius = half of diameter =
`(diamter)/(2)`

Radius =
`(34)/(2)` = 17km

Now we can find the area of the semi circle.

The value of pi is taken as 3.14

`(3.14 . 17^(2) )/(2)` (The dot between the 3.14 and
`17^(2)` shows that you have to multiply both of them)

=
`(3.14 . 289)/(2)`

=
`(907.46)/(2)`

Area of the semi circle = 453.73
`km^(2)`

Answer 2

RED 453.73km

Explanation:

So what I'm going to do is find the area of it as if it was a full circle then cut it in half.

So the formula to find the area of a circle is A =
`\pi r^(2)`

So to find r (radius) cut the diameter in half. 34/2 = 17

Plug in

A =
`\pi 17^(2)`

A = 907.46

Now cut it in half

453.73km would be the answer

HOPE THIS HELPS YA!!!