Answer:
9
Step-by-step explanation:
The reason why it is 9 is because if you look to the bigger triangle, you can see that 15 is 3/4 the size of 20, so once you find what number is 3/4 of 12, you have the answer, 9! Hope this helps!
1 line of symmetry through the middle making 2 v s
thirty four thousand six hundred and eighty eight
1.98