If only 1/4 of the parent material is left and the half-life of the element is 10,000 years, how old is this sample?
O A. 2500 years
B. 5000 years
O C. 20,000 years
O D. 30,000 years.

d 25 pi/6

step-by-step explanation:

the diameter is 10 inches

the radius is 1/2 of the diameter or 5 inches

the area of the circle is

a = pi r^2

  = pi 5^2

  = 25 pi

the slice is 60 degrees of the entire circle.

60 degrees out of 360   60/360 = 1/6

the area of the slice is 1/6 of the circle

a slice = 1/6 a circle

a slice = 1/6 * 25 pi

wait nvm i know the correct answer now its 100%   81 square feet

~batmans wife dun dun

plz mark brainliest i took the test