Hi, I'm happy to help!
First, we need to find BC. We know, because B is the midpoint of AC, that AB and BC are congruent, or the same length. We are told that AB is 3.
<u>So, BC is 3 also.</u>
Next, we need to find AC. AC is a combination of AB and BC, so, we just add them.
3+3=6
<u>AC is 6.</u>
Finally, we need to find DE. We know that AC and CE are congruent because of this sign: ≅. This means they are the same length. We can then know that CE is 6 also. To find DE we need to take the length of CD away from CE. We know that CD is 2, so now, we subtract.]
6-2=4
<u>DE is 4.</u>
<u></u>
I hope this was helpful, keep learning! :D
