Answer:
The coordinates of A is 
 .
.
Explanation:
We are given that a triangle ABC is rotated 180 degrees about the origin .
We have to find the coordinates of A.
Let vertices of triangle ABC 

When we rotate the about 180 degrees then the coordinates changes like as

When we rotate triangle ABC about 180 degrees then its vertices Ais (
 change into
 change into 

Hence, the coordinates of A is 
 .
.