In △ ABC, ∠ ACB = 90 °, De is the median line of △ ABC, point F is on the extension line of BC, and ∠ CDF = ∠ a

In △ ABC, ∠ ACB = 90 °, De is the median line of △ ABC, point F is on the extension line of BC, and ∠ CDF = ∠ a

1. Points D and E are the midpoint of AC and ab respectively
∵ points D and E are the midpoint of AC and ab respectively
The De is the median of △ ABC
∴DE∥BC
That is, de ‖ CF (CF and BC are in a straight line) （1）
∵∠ACB=90°=∠DCF
∠CDF=∠A
∴∠F=∠B
CE is a right triangle ABC, and the hypotenuse AB is the center line
∴CE=BE
∴∠ECB=∠B=∠F
‖ DF ‖ Ce (same position angle) （2）
The decf is a parallelogram
2. Points D and E are the midpoint of AB and AC respectively
The conclusion is not true