Question

find the perpendicular distance of A (10,12) from the y axis

Answer 1

The perpendicular distance of A (10,12) from the y axis is equal to abcissa.

Hence 10 is answer.

Hope it's helpful to u.

Answer 2

The point on the y-axis is (0, 12)

Distance between (10, 12) and (0, 12)

$\bf\huged=\sqrt{(0-10)^2+(12-12)^2}$

$\bf\huge =\sqrt{100+0}$

= 10 units