Straight lines that never meet An exact position A straight length without width that extends infinitely in both directions Point, line, parallel lines, perpendicular lines. Straight lines that never meet Lines that meet at right angles

B A C D Notice the symbols that help us to know when lines are definitely parallel or perpendicular. E F

It doesn’t matter how long the ‘arms’ of the angle are, you still have to turn the same amount to get from one to the other.

A B F C Three letters help us define an angle, but we also need to specify which angle we are referring to, by describing its size, e.g. acute, obtuse, or reflex. The symbol for angle is not always used. D E

A B F C D E

A B F C D E

A B F C D E

A D B How much then is a quarter turn? Half turn? The turn from A to B? A to C? A to D? A back to A? C

B Which of these estimates are likely/impossible?

A B ?° 320°

A ?° C B A 125° ?° C B

O

O There are two angles of 10 degrees. These are called opposite angles. There are also two other angles, what are these? Why are they also equal?

O 35° ?°