Kiểm tra 1 tiết môn: Toán lớp 8

Họ Tên: 
Lớp: 8A
KIỂM TRA 1 TIẾT
 Môn: Toán
Điểm
Lời phê của thầy giáo
Câu 1: (2đ)
	a) Phát biểu định lí tổng bốn góc trong một tứ giác.
	b) Cho tứ giác ABCD, biết , . Số đo góc C gấp đôi góc A. Tính số đo góc D.
	Câu 2: (3đ)
	a) Phát biểu định nghĩa, tính chất đường trung bình của tam giác.
	b) Cho tam giác ABC. Gọi D là trung điểm AB, E là trung điểm của cạnh AC. Tính độ dài cạnh BC biết DE = 4 cm.
	Câu 3: (2đ)
	Nêu các dấu hiệu nhận biết hình bình hành.
	Câu 4: (3đ)
	Cho tam giác ABC. Gọi AM là đường trung tuyến ứng với cạnh BC. Cho điểm D đối xứng với A qua điểm M.
	a) Chứng minh rằng tứ giác ABDC là hình bình hành.
	b) Để tứ giác ABDC là hình chữ nhật phải cần thêm điều kiện gì với tam giác ABC.
BÀI LÀM
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