Answer:
y = x + 3 or y = x - 3
Explanation:
Rise over run for slope (m) and then get the y-intercept (b) by continuing the pattern from right to left until you cross the y-axis.
Plug m and b into y = mx + b
side p and side r are both perpendicular to side s.
Side p:
y = x + 3
Side s:
y = x - 3