As shown in the figure, in the trapezoidal ABCD, AD / / BC, ab = CD, e is the midpoint of BC It's in the mathematics evaluation manual of the ninth grade volume I of Jiangsu Education Press.

As shown in the figure, in the trapezoidal ABCD, AD / / BC, ab = CD, e is the midpoint of BC It's in the mathematics evaluation manual of the ninth grade volume I of Jiangsu Education Press.

In ladder ABCD, AD / / BC, ab = CD,
Trapezoid ABCD is isosceles trapezoid,