AMC8 1991

AMC8 1991 · Q10

AMC8 1991 · Q10. It mainly tests Area & perimeter, Coordinate geometry.

The area in square units of the region enclosed by parallelogram ABCD is

平行四边形 ABCD 所围区域的面积（平方单位）是

(A) 6 6

(B) 8 8

(D) 15 15

(E) 18 18

Answer

Correct choice: (B)

正确答案：（B）

Solution

The parallelogram rests on the horizontal axis. Since the coordinates of point C are (4, 2), it follows that the height of the parallelogram is 2. Since point B is (0, 2), it follows that the length of the base BC is 4. The area of a parallelogram is base times height. Thus the area is $4 \times 2 = 8$.

平行四边形位于水平轴上。点 C 的坐标是 (4, 2)，因此平行四边形的高度是 2。点 B 是 (0, 2)，因此底边 BC 的长度是 4。平行四边形的面积是底乘高，因此面积是 $4 \times 2 = 8$。

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