- Parallel and perpendicular lines - Right, acute and obtuse angles - Measuring and drawing angles and distances

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Slide 1: Slide

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This lesson contains 14 slides, with text slides and 5 videos.

Lesson duration is: 50 min

Items in this lesson

Recap CH5

- Parallel and perpendicular lines - Right, acute and obtuse angles - Measuring and drawing angles and distances

Slide 1 - Slide

Parallel lines

Lines a and b are parallel to each other. Lines c, d and e are parallel to each other.

Notation:

Slide 2 - Slide

Perpendicular lines

Lines s and t are perpendicular to each other.

Notation:

Slide 3 - Slide

Angles & Degrees

A right angle is 90° An acute angle is between 0° and 90° An obtuse angle is between 90° and 180°

right angle acute angle obtuse angle 90° between 0° and 90° between 90° and 180°

Slide 4 - Slide

Slide 5 - Video

Slide 6 - Video

Slide 7 - Video

Slide 8 - Video

Slide 9 - Video

Symmetry

There are two types of symmetry: - Reflection symmetry - Rotation symmetry Figures can have no symmetry, one type of symmetry or two types of symmetry.

Slide 10 - Slide

Reflection symmetry

If a figure could be folded in half, so both halves fit exactly on top of each other, we say a figure has reflection symmetry. The line on which you would fold the figure is called the axis of symmetry.

Slide 11 - Slide

Rotation symmetry

If a figure can be rotated less half a turn or less and fit exactly on themselves again, we say a figure has rotation symmetry. If a figure fits onto itself after a quarter, a half and three quarters of a turn, we say it has rotation symmetry through 90°, 180° and 270°.

120° and 240° 60°, 120°, 180°, 240° and 300°

Slide 12 - Slide

Rotation symmetry

This figure has 7 identical parts, so 1/7th of a turn will make it fit onto itself again.