In △ ABC, BD = 2dc, AE = be. It is known that the area of △ ABC is 18 square centimeters, then the area of quadrilateral AEDC is equal to______ Square centimeter

In △ ABC, BD = 2dc, AE = be. It is known that the area of △ ABC is 18 square centimeters, then the area of quadrilateral AEDC is equal to______ Square centimeter

Connect ad, because BD = 2dc, so s △ abd = 2S △ ADC, that is, s △ abd = 18 × 23 = 12 (square centimeter), and because AE = be, so s △ ade = s △ BDE, that is, s △ BDE = 12 × 12 = 6 (square centimeter), so the area of AEDC is: 18-6 = 12 (square centimeter), so the answer is: 12

In triangle ABC, BD = 2dc, AE = be. Given that the area of triangle ABC is 18 square centimeters, how many square centimeters is the area of quadrilateral AEDC equal to?

Even EC, because AE = EC
∴S△CAE=S△CEB=S△ABC=18/2=9
BD=2DC ∴CD=BC/3
∴S△CED=S△CEB/3=9/3=3
The area of quadrangle AEDC = s △ CAE + s △ CED = 9 + 3 = 12 (square centimeter)

A trapezoid, if the upper bottom is reduced by 4cm, becomes a triangle, and the area is reduced by 12cm2 compared with the original trapezoid. If the upper bottom is increased by 4cm, it becomes a parallelogram. What is the area of the original trapezoid? I will offer a reward

It can be concluded from the title: the upper bottom is 4cm, and the lower bottom is 4cm more than the upper bottom, then the lower bottom is 4 + 4 = 8cm
Height: 12 × 2 △ 4 = 6cm
Area: (4 + 8) × 6 △ 2 = 36 square centimeter