1. Two angles are acute, while the other is square
2. They all add up to 180°
Answer:
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.
Answer:
C) 60
Step-by-step explanation:
180 - 120
Answer:
29
Step-by-step explanation:
Simplify the expression 
step by step:
1.
2.
Now,
