Answer:
12
Step-by-step explanation:
These are similar triangles, so the ratio of their sides is the same for each side.
AB = 8 and BD = 10
So, the ratio is 8:10 or 4:5
Because the triangles are similar....
The ratio of AC:CE is also 4:5
12:15 = 4:5
So, 12 is the answer!
