Find the missing coordinate

Answer:
(0, -10a)
Step-by-step explanation:
From the picture attached,
Coordinates of a point have been given as (-10a, 0)
x-coordinate → distance of the point from the origin on x-axis
y-coordinate → distance of the point from the origin on y-axis
Therefore, distance of the given point on x-axis = -10a [(-) sign denotes the negative side of the x-axis]
Distance of the other point with unknown coordinates (x, y) (on y-axis) from the origin = y
And y = 10a
Therefore, coordinates of the unknown point will be (0, -10a).
[Here (-) sign denotes the negative side of the y-axis]