第13页

信息发布者:
B
D
B
直角
$60^{\circ}$
$30^{\circ}$
$70^{\circ}$
$40^{\circ}$
解:$\because\angle CEF = \angle AED = 48^{\circ},$$\angle ACB=\angle CEF+\angle F,$
$\therefore\angle F=\angle ACB - \angle CEF=74^{\circ}-48^{\circ}=26^{\circ}。$
$\therefore\angle BDF = 180^{\circ}-\angle B-\angle F=180^{\circ}-67^{\circ}-26^{\circ}=87^{\circ}$