Make a vertical line from point A to BC, with the vertical point F to get AF, from point E to BC to get EG, and with the vertical point G to get equilateral triangles EGB and AFB.
The area of quadrangle AECD = the area of trapezoid ABCD minus the area of triangle EBC.
Let the length of EG be x and the length of AD be y, and we get:
The area of triangle EBC = 1/2*BC*EG=5/6*XY.
The area of quadrangle AECD = the area of trapezoid ABCD minus the area of triangle EBC =1/2 * (ad+BC) * AF-1/2 * BC * eg, and the result is 1 1/6XY.
The ratio of 5/6XY is11/6xy = 5:11.
The difficulty is low, suitable for students who have just learned the triangle part to pra