# Perpendicular and parallel straight lines 1 1/2

• Lesson Aims
• During the folding processes the pupil will relate to perpendicular and parallel lines and segments.

• Name of Model
• There is no model in this lesson.

• The Lesson Structure
• According to planned curriculum.

• Lesson content
• This is a prepatory lesson to the next lesson about parallel and perpendicular lines and segments with the model of a dress. In the lesson the pupils investigate the properties of parallel and perfpendicular lines using  their measuring tool.

• Prior Knowledge
• The concepts of angle,a right angle and a square.

• Materials
• Origami sheets 15/15 cm and measuring tool.

• Additional knowledge
• For the teacher.

If two straight segments are  both perpendicular to a third straight line then the two segments are parallel.

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A  transversal line that is perpendicular to one of two parallel lines will also be perpendicular to the other parallel line.