Answer:
36 degrees
Step-by-step explanation:
So, first of all, the interior angles of any triangle add up to 180.
First, you add up all the numbers in the ratio.
13+23+9=45
180/45=4 [To find out how much each piece really equals]
So, now that we know what each piece equals, the most acute triangle was the one that said '9' in the ratio.
4*9=36
Hope it helped, tell me if it's wrong, I'll correct it.