Download HOW TO NAME AN ANGLE

HOW TO NAME AN ANGLE
Geometry is an important topic in maths. Every major exam through to year 12 will contain
questions relating to geometry.
An angle is made up of two rays which meet at a common point called a VERTEX.
For example, BA and BC are the arms of the angle
Which meet at the VERTEX B.
A
x
B
There are four main ways of naming the above angle
i)
ABC or
CBA
ii)
ABˆ C
CBˆ A
iii)
B
iv)
x̂
or
C
NOTE: i)
ii)
iii)
The vertex must always be the middle letter when using methods (i) and (ii)
B can only be used if there is no possibility of confusion.
Often the angle is actually marked with a small letter as shown in the example
above as x̂
Example:
Name the 2 angles shown in the diagram.
P
Q
Solution:
S
R
Any of the following answers would all be correct for the unshaded angle:
PSR
or
RSP or PSˆR or RSˆP or S
Any of the following answers would be correct for the shaded angle:
PRQ
NOTE:
or
QRP
or
PRˆ Q
or
QRˆ P
R by itself could not be used to describe the shaded angle because of possible
confusion with the angle right next to it.