Mô tả phương pháp chung của bài toán tìm khoảng ước lượng tham số. Giúp mình với ạ

Giving ad is congruent to bc and angle bcd is congruent to angle adc prove d e is going to ce

(05.02) mr. morris is going to save money and replace his sailboat's mainsail himself. he must determine the area of the mainsail in order to buy the correct amount of material. calculate the area of the parallelogram to determine how much material should be purchased. be sure to explain how to decompose this shape into rectangles and triangles. describe their dimensions and show your work.

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.