Answer:
It helps you know if the answer is reasonable because when you do the work and get your answer, you can check if it is close to your estimate, and if it is, it is most likely correct. On the other hand if it is not close to the estimate it is most likely wrong, unless you estimated incorrectly.
Step-by-step explanation:
Answer: I believe those would be opposite angles (aka vertically opposite angles).
Answer:
69, nice
Step-by-step explanation:
118-49=69
Answer:
20:5 - If you're going to simplify it, do 20/5 which is 4/1.
Step-by-step explanation:
