# [SOLVED] Find the degree of the angles

• September 25th 2008, 10:27 PM
fabxx
[SOLVED] Find the degree of the angles
In the figure below, what is the sum, in terms of n, of the degree measure of the four angles marked with question marks (?)

a) n
b)2n
c) 180-n
d) 360-n
e)360-2n

- - - - -615

$\angle AOB=n$
Note that $\angle {\color{red}AOD}=180-n$
But we know that $\angle OAD+\angle ODA+\angle AOD=180$
Hence $\angle OAD+\angle ODA=180-\angle {\color{red}AOD}=180-(180-n)=n$
Similarly, we have $\angle OBC+\angle OCB=n$