Quadrilaterals (I)
Line segments, the shortest path between two points; quadrilaterals as four line segments joined up, and their sides, angles, vertices, opposite sides and adjacent sides; the properties of squares and rectangles: four right angles, with all sides equal in a square and opposite sides equal in a rectangle; and drawing them on squared paper.
Key words
| Chinese | English |
|---|---|
| 線段 | line segment |
| 四邊形 | quadrilateral |
| 正方形 | square |
| 長方形 | rectangle |
| 對邊 | opposite side |
| 鄰邊 | adjacent side |
The 9 short lessons and the chapter test
Lessons are in Chinese for now.
- 線段
- 四邊形
- 對邊和鄰邊
- 正方形和長方形
- 長方形的邊
- 方格紙上的圖形
- 對還是錯
- 分辨四邊形
- 重溫
- 章節測驗 (chapter test)
Sample questions (in Chinese)
Question 1甲、乙、丙三條線都連接 A 和 B。哪一條最短？
- 丙
- 乙
- 甲
Answer and explanation
答案：B．乙
為甚麼？連接兩點的直的線叫線段，它是所有連線中最短的。線乙是直的，所以最短。
Question 2下面哪一個是四邊形？
Answer and explanation
答案：A
為甚麼？四邊形由 4 條線段首尾相連組成，有 4 條直的邊和 4 個角。有缺口、有彎曲的邊或邊數不是 4 的，都不是四邊形。
Question 3在四邊形 ABCD 中，DA 的對邊是哪一條？
- AB
- CD
- BC
Answer and explanation
答案：C．BC
為甚麼？對邊是不連在一起的兩條邊；鄰邊是連在一起的兩條邊。DA 的對邊是 BC，鄰邊是 AB 和 CD。
Question 4這個四邊形是正方形、長方形，還是其他四邊形？
- 正方形
- 其他四邊形
Answer and explanation
答案：A．正方形
為甚麼？四條邊都是 4 厘米，四個角都是直角，所以是正方形。
Based on learning unit 2S4 of the Education Bureau’s Primary Mathematics Curriculum (2017).