Question

Write the rules for sign convetion​

Answer 1

Rules for sign convention :

All distances should be measured from the pole.

The distances measured in the direction of incident light, to be taken positive and measured in the opposite direction of incident light to be taken negative.

Answer 2

$\huge \bf \underline{answer} \:$

⭐The diagrams are drawn with the incident light travelling from left to right.

⭐The distances are measured by taking pole as the origin.

⭐The distances measured in the direction of incident light are taken positive while those measured in the direction opposite to it are taken as negative.

⭐Heights measured upward and perpendicular to the principal axis are taken as positive while those measured downwards are negative.

_________☺