Answer:
The coordinates of point C are (a,0).
Explanation:
Given information: ABC is right isosceles triangle.
From the given figure it is noticed that the side BC is hypotenuse of the triangle ABC.
By pythagoras theorem,



Therefore hypotenuse cannot be equal to leg. So, we can say that in triangle ABC,

Length of AB is

From the figure it is noticed that the point C lies on the x-axis, therefore the y-coordinates of C is 0.
Let the coordinates of C be (x,0) and length of AC must be a.


Therefore coordinates of point C are (a,0).