We can find the area of the triangle using the formula:
A = 1/2 * base * height
where the base is the distance between points A and B, and the height is the distance between point C and the line containing points A and B.
The distance between points A and B is:
AB = |-10 - 0| = 10
The line containing points A and B is the x-axis, so the height of the triangle is the y-coordinate of point C, which is 6 units away from the x-axis. Therefore, the height is:
h = 6
The area of the triangle is:
A = 1/2 * base * height
A = 1/2 * 10 * 6
A = 30 square units
Therefore, the area of the triangle whose vertices are A (0, 0), B(-10, 0), and C(0, -6) is 30 square units.