For shape 1, you first need to find the radius to then find the area of a circle. Which is 394.08. Since this isn't a full circle, you will need to divide it by 2 to get 197.04. For shape 2(Easiest to find) You do 11.2*11.2 to get the answer of 125.44. And lastly for shape 3, you can basically do the same as what you did for shape 2. But since it is a triangle, you divide your answer by 2, to get the answer of 62.72.
P ( A ) = 0.45 - probability that the land has oil, P ( B ) = 0.8 - probability that the test predicts it P ( A ∩ B ) = P ( A ) · P ( B ) = 0.45 · 0.8 = 0.36 Answer: The probability that the land has oil and the test predicts it is 36 %.
