Answer:

Explanation:
The picture of the question in the attached figure
we know that
The measure of the external angle is the semi-difference of the arches it covers.
so
![m\angle GET=(1)/(2)[arc\ TN-arc\ TG]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/e070smp2lfisci3t351oqmxkok1hvi78xg.png)
Remember that the diameter divide the circle into two equal parts
In this problem
TN is a diameter
we have
----> because is half the circle (TN is a diameter)
---> is given
substitute
![m\angle GET=(1)/(2)[180^o-46^o]=67^o](https://img.qammunity.org/2021/formulas/mathematics/middle-school/ef6brouiznf6ou3mnahqjjznbzgg5b85ng.png)