Unit 4 lines and angles

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Unit 4 Geormetry

Lines and Angles

Notation

Points are indicated with capital letters (point A, point B, etc)
Lines are indicated with a small letter (line k, line l, etc)

Line segments (sometimes called
lines too) connect two points, they
are indicated with the letters of the
two points (line segment BC, PQ, etc)

Parallel lines

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

Notation:

Perpendicular lines

Lines s and t are perpendicular to each other.

Notation:

What does a//b mean?

1. a divided by b
2. line a is parallel to line b
3. line a is perpendicular to line b
4. a or b

Drawing parallel and perpendicular lines

When drawing parallel and perpendicular lines, you have to use your setsquare (in the tb. geotriangle) and a sharp pencil.

Polygons

(From the Greek πολύς (polús) "much" or "many" and γωνία (gōnía) "corner" or "angle")

A figure with 3 edges/vertices is called a triangle.

                                                           A figure with 4 edges/vertices is called a quadrilateral.

A figure with 5 edges/vertices is called a pentagon.

                                                           A figure with 6 edges/vertices is called a hexagon.

A figure with 8 edges/vertices is called an octagon.

How many sides does a pentagon have?

1. 4
2. 5
3. 6
4. b

Quadrilaterals

Some quadrilaterals have their own name:
Square:


Rectangle:

Diagonals

The diagonals in a polygon are the line segments that connect each vertex to the opposite vertices.

Homework Monday

Make and correct from §5.1:
2, 4, 5, 6, 8, C2

Bring your notebook, textbook and workbook,
a geotriangle and a pair of compasses

Out of the blue:

Next lesson: Bring your PAIR of COMPASSES too!

(To draw CIRCLES, in §5.2)