Respuesta :

Answer:

x=28

Step-by-step explanation:

So first slove for the right angle triangle

a²+b²=c²

a=12 and c=15

12²+b²=15²

144+b²=225

b²=225-144

b²=81

b=√81

b=9

so now that you know the top two sides add 10 due to the lenght given on the bottom

9+10+9=28