Answer:
Step-by-step explanation:
The top triangle is similar to the whole triangle because of AAA
Then we know that the corresponding sides are similar
9/81=(3x-20)/(3x-20+56)
1/9=(3x-20)/(3x+36)
cross multiply
9(3x-20)=3x+36
27x-180=3x+36
24x=216
x=9
