Explanation:
Dilations do not change your angles, so although the length does change, your angles will not. So for your answer, the angles will be the exact same.
For the length, all you have to do is multiply each side by 5/2.
8: Multiplied by 5/2 is 20
9: Multiplied by 5/2 is 22.5
7: Multiplied by 5/2 is 17.5
The lengths are getting larger because they're being dilated by a number greater than 1.
I hope this helps :)