The triangles are similar by??

the SAS similarity theorem

The mother's ironing is the main symbol of the story because it reflects on her hopes for Emily. As the mother irons she discusses Emily's life. Through her narration, readers can understand that the mother wanted a smooth life for Emily. But struggles like poverty, unexpected illness, and other negative experiences prevented a normal life for Emily. The iron indicates that the mother wanted to fix Emily. Her sentiments also can be interpreted as regrets that the mother could not help Emily overcome life trials. The ironing can therefore be seen by the readers like the heaviness of a mother's duties towards a child. The continuous action of ironing shows the mother's efforts to address Emily's problems in doing daily tasks.  The mother cannot help but reflect upon the reasons Emily developed into a special child. Most importantly, the iron represents that the mother still believes Emily can become a confident person. With the mother's support, Emily may have hope.