Transcript What are trapeziums

Find the characters of a trapezium
Group activity
Now make your own trapezium
Fill in the blanks
①
②
Quadrilateral
③
⑥
④
( ①③④⑤⑥
⑤
)
A quadrilateral with one pair of parallel opposite sides
（
①④⑤⑥
）
A quadrilateral with only one pair of parallel opposite sides
trapezium
( ①④⑤ )
Say the names of all parts
upper base
upper base
side
①
side
side
upper base
side
⑤
④
lower base
lower base
side
side
lower base
What’s the difference between the bases
and the sides?
upper base
lower base
From a point on the upper base, we can draw a
perpendicular line segment toward the lower base.
The perpendicular line segment is the height of
this trapezium.
Draw the height of each trapezium：
h
h
h
From “B” draw the height
A
From“A”draw the height
h
D
h
B
C
Which height is right？
Which height is right？
In a trapezium,if there is a right angle,
we call it a right angle trapezium.
True or false
1)There
are only two heights in a trapezium.
（×）
2) Upper base must be longer than lower base.（×）
3)There are two right angles in a right angle trapezium.
√）
（
play：Use scissors to cut the triangle
once to make a trapezoid.
Use scissors to cut the parallelogram
once to make a trapezoid.
play：