Answer:
Ethan and Isabella are 9 meters apart.
Explanation:
1. We can solve this using the Pythagorean Theorem, a²+b²=c².
2. Mrs. Gretta is standing 12 meters in front of Ethan, so a=12.
3. Isabella is sitting to Ethan's right, but we don't know how far away, so b=x.
4. Mrs. Gretta is 15 meters from Isabella, so c=15.
5. Plugging these variables into the equation, we get 12²+x²=15² which equals 144+x²=225.
6. We can move 144 to the other side to get x²=81, then square the 81 to get x=9.
7. Therefore, the answer is 9. Ethan and Isabella are 9 meters apart.