1. Parallelogram

2. Which of the following are parallel lines?
(1) (2) (3)
(4) (5) (6)

3. Parallelogram Can you see a shape here?
Which of the following are parallel lines?
Parallelogram
(1) (2) (3)
(4) (5) (6)

5. A B D C
AB∥CD
AD∥BC
symbol：
written as：
ABCD

6. Which of the following shapes are parallelograms?① ② ③ ④ D E F G
（ ） ×
（ ） √
（ ） ×
（ ） √

7. diagonal AC diagonal BD
How many diagonal lines are there in a parallelogram? Can you show it? A D B B C
diagonal AC
diagonal BD

8. If you cut along one of the diagonal lines, what shapes can you get?B C
A parallelogram can be divided into two identical triangles.
AB＝CD，AD＝BC
∠B＝∠D
∠A＝∠C

9. There are groups of opposite edges;
Each group is (parallel or not parallel);
The length of each group is (equal or unequal);
This shape is called a 2
parallel
equal
parallelogram

10. There are groups of opposite edges;
Each group is (parallel or not parallel);
Length of each group is (equal or unequal);
Adjacent edges are
(perpendicular or not perpendicular) to each other;
This shape is called a 2
parallel
equal
perpendicular
rectangle

11. Adjacent edges are (perpendicular or
not perpendicular) to each other;
The length of all sides is (equal or unequal);
This shape is called a
perpendicular
equal
square

12. parallelogram
rectangle
square

13. Squares are a special kind of rectangle.
Parallelogram
Squares are a special kind of rectangle.
Squares and rectangles are special kinds
of parallelograms.

14. × × √ Judge Any two triangles could make a parallelogram. ( )
In a parallelogram, the 4 angles must be equal. ( )
In a parallelogram, the opposite sides are the same length. ( ) × × √

15. Calculate the perimeter of the parallelogram
15＋8＋15＋8
＝23＋15＋8
＝38＋8
＝46(cm) E G F H
15 cm
8cm
15×2＋8×2
＝ 30＋16
＝ 46(cm)
2×(15＋8)
＝ 2×23
＝ 46(cm)

16. How many parallelograms are there in this image?