As shown in the figure, in △ ABC, e is a point on the edge of BC, EF is perpendicular to BC, intersects BA at D, intersects the extension line of Ca at F, if ad = AF, is △ ABC an isosceles triangle

As shown in the figure, in △ ABC, e is a point on the edge of BC, EF is perpendicular to BC, intersects BA at D, intersects the extension line of Ca at F, if ad = AF, is △ ABC an isosceles triangle

ABC is an isosceles triangle, which is equal by the remainder of an equal angle