Answer:
You can identify whether your answer is correct or not and/or easily solve for an answer.
Step-by-step explanation:
To see if things make sense, estimating an answer can give you that clarification. More so, in high school geometry, you tend to get lots of decimals and radicals and all sorts of crazy numbers so estimation can really help. I hope that helps you. If that was not what you were looking for please feel free to ask.
