<span>60.5 milligrams per square centimeter
First, determine how many half lives have expired by dividing the time by the half-life. So:
55/20 = 2.75
That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount.
9 / 0.148650889 = 60.5445419
So originally, there was 60.5 milligrams per square centimeter 55 years ago.</span>
Top box is 2x
bottom box is 3
Answer:
what does that mean
Step-by-step explanation:
If these 2 triangles are similar to each other, the corresponding sides have to exist in proportion to one another. The angles would be exactly the same (side length doesn't matter at all!). Going from the bigger triangle to the smaller, KL corresponds to RS; LJ corresponds to SQ; JK corresponds to QR. The ratio of KL:RS is 5:1; the ratio of LJ:SQ is 5:1; the ratiio of JK:QR is 5:1. That means that the sides are all proportionate and the triangles are similar by the SSS postulate. Now that we know that the triangles are similar, we can say that all the corresponding angles are the same by CPCTC but we had to determinte side similiarity first. Your answer is the second choice, SSS