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]