Explanation:
It is assumed EF and CB are parallel.
The triangles ACB and AEF are similar by SAS as:
- CAB is common angle
- AC and AE overlap
- AB and A F overlap
Confirm if corresponding sides have same ratios:
- AC / AE = AB / A F
- (8 + 4) / 8 = (10 + 5) / 10
- 12/8 = 15/10
- 1.5 = 1.5
Confirmed