Ta có: .
Vì .
.
Ta có: vuông tại .
.
Xét tam giác vuông có: .
.
.
Vậy . Chọn C.
Questions 26-30: Each of the following sentences has one error (A, B, C, or D). Find it and blacken your choice on your answer sheet.
Fertilizer is a substance added to soil to making plants grow more successfully.