A point P lies on the x-axis and another point Q lies on the y-axis.

(i) Write the ordinate of point P.

(ii) Write the abscissa of point Q.

(iii) If the abscissa of point P is -12 and the ordinate of point Q is -16; calculate the length of line segment PQ.

(i) The point P lies on the x-axis, so its co-ordinates are (x, 0).

The ordinate of point P is 0.

(ii) The point Q lies on the y-axis, so its co-ordinates are (0, y).

The abscissa of point Q is 0.

(iii) If the abscissa of point P is -12, then P = (-12, 0).

And if the ordinate of point Q is -16. So, then Q = (0, -16).

The length of the line segment PQ

$= \sqrt{(x$2 - x1)^2 + (y2 - y1)^2}\\[1em] = \sqrt{(0 - (-12))^2 + ((-16) - 0)^2}\\[1em] = \sqrt{(-12)^2 + (-16)^2}\\[1em] = \sqrt{144 + 256}\\[1em] = \sqrt{400}\\[1em] = 20

Hence, the length of PQ = 20.