Cho hình thoi ABCD có góc A = 60 độ. Qua C kẻ đường thẳng d cắt tia đối của các tia BA, DA theo thứ tự ở E ,F Chứng minh rằng:

a EB/BA = AD/DF

b tam giác EBD đồng dạng với tam giác BDF
c) BID=102 độ

Scott harris can invest $7,000 in a 1-year cd that earns interest at an annual rate of 4 percent compounded monthly. the amount per $1.00 is 1.040742. he can also invest $7,000 in a 1-year cd at annual rate of 4 percent compounded quarterly. the amount per $1.00 is 1.040604. what is the difference in the amount of interest earned for each investment? a) $0.96 b) $0.81 c) $0.87 d) $0.88