Find the area of the semicircle. 10

Exact Area = 25pi   square units

Approximate Area = 78.5  square units

The approximate value is found using pi = 3.14

Explanation:

I think you meant to say "quarter circle" instead of "semicircle".

The area of a full circle with radius r = 10 is

A = pi*r^2

A = pi*10^2

A = pi*100

A = 100pi

But we only want one quarter of this. So we divide the full area by 4

(100pi)/4 = (100/4)pi = 25pi

The exact area in terms of pi is 25pi square units

If we used the approximation pi = 3.14, then we can say 25*pi = 25*3.14 = 78.5 is the approximate area

To get a better approximation, use more decimal digits in pi.

1760 kilometers

step-by-step explanation:

multiply the amount of time the plane took to travel by it's speed