Respuesta :

Answer:

see

Step-by-step explanation:

1.

AD²+BD²=AB²

AD²+12²=15²

AD²+144=225

AD²=225-144

AD²=81

AD=√81

AD=9

2.

AC=AD+DC

AC=9+16

AC=25

3. I don't know what's the answer here.

Please give me brainlist.