1.1. Knowledge to remember
Trapezoid ABCD has:
- Bottom edge AB and bottom edge DC. Side AD and side BC.
- The bottom two sides are two parallel opposite sides.
A trapezoid has a pair of parallel opposite sides.
1.2. Solve textbook exercises on pages 91 and 92
Lesson 1 of the textbook page 91:
Which of the following figures is a trapezoid?
Observing the figure, we see: figure 1, figure 2, figure 4, figure 5, figure 6 is a trapezoid
Lesson 2 Textbook page 92:
Which of the three pictures below has:
– Four sides and four angles?
– Are two pairs of opposite sides parallel?
– Only one pair of opposite sides parallel?
– There are four right angles?
– Figure 1, figure 2, figure 3, each shape has 4 sides and 4 corners.
– Figure 1, figure 2, each figure has two pairs of opposite parallel sides.
– Figure 3 has only one pair of parallel opposite sides.
– Figure 1 has 4 right angles
Lesson 3 Textbook page 92:
Draw two more lines to each of the shapes below to get a trapezoid:
Two lines can be added to each figure as follows:
Note: there are many ways to draw two more lines to each given figure to get a trapezoid, students choose the appropriate way.
Lesson 4 Textbook page 92:
Trapezoid ABCD has which angles are right angles? Which side is perpendicular to the two bases?
A trapezoid with one side perpendicular to the two bases is called a right trapezoid
Trapezoid ABCD has angle A and angle D as right angles.
Side AD is perpendicular to the two bases.