I need help on this question please and explanation

Answer:
RED 453.73km
Step-by-step 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 = [tex]\pi r^{2}[/tex]
So to find r (radius) cut the diameter in half. 34/2 = 17
Plug in
A = [tex]\pi 17^{2}[/tex]
A = 907.46
Now cut it in half
453.73km would be the answer
HOPE THIS HELPS YA!!!
Answer:
453.73 [tex]km^{2}[/tex] (the last option, in red)
Step-by-step 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:
[tex]\frac{\pi r^{2} }{2}[/tex] where r is the radius.
Since the diameter is given, we have to first find the radius of the circle.
Radius = half of diameter = [tex]\frac{diamter}{2}[/tex]
Radius = [tex]\frac{34}{2}[/tex] = 17km
Now we can find the area of the semi circle.
The value of pi is taken as 3.14
[tex]\frac{3.14 . 17^{2} }{2}[/tex] (The dot between the 3.14 and [tex]17^{2}[/tex] shows that you have to multiply both of them)
= [tex]\frac{3.14 . 289}{2}[/tex]
= [tex]\frac{907.46}{2}[/tex]
Area of the semi circle = 453.73 [tex]km^{2}[/tex]