Lines, Angles and Shapes

1
Lines, Angles and Shapes
22 November 2009
Here are some facts about angles that you should
know
A square corner like this is called a RIGHT
ANGLE It measures 900 (90 degrees)
900
2
Push
Push
900
900
Push
Push
900
900
900 900 1800
1800 on a straight line
3
Prove that x y z 1800
b
d
y
x
z
a
Line ab is parallel to line cd so
c
4
d
y
x
z
x
This angle must be x degrees
c
Line ab is parallel to line cd so
5
This angle must be y degrees
y
These are scissor angles so
d
y
x
z
x
c
6
This angle must be y degrees
y
d
y
y
x
z
x
These lines make corresponding angles so
c
7
y
d
y
y
x
z
x
x, y and z make a straight line so these angles
must add up to give a total of 1800
c