Answer:
EC = 15
Step-by-step explanation:
It appears that D, E, and F are the midpoints of their respective line segments (chords of the circumcircle). Hence EB = EC = 15.
2 3 5 7 11 13 17 19 23 31 41 43 53 59
the answer is 31
Step-by-step explanation:
hfndjwldnj4
If we want to calculate a, then cos(60°) = a/12, but we know that cos(60°) = 1/2,
then 1/2 = a/12 and a = 6
If we want to calculate b, then sin(60°) = b/12, but we know that cos(60°) = (√3)/2
then (√3)/2 = b/12 and b = 6√3
Half-Life = ln (.5) / k
Half-Life = .693147 / .00011
Half-Life =
<span>
<span>
<span>
6,301 years
For a radioactive substance to decay to 25%, it has to go through 2 halflives.
2 * 6,301 = 12,602 years
approximately 12,600 years
</span></span></span>
