Since the shape is a rectangle, the slope of the opposite side include the following:
D. opposite side: -3/2
other sides: 2/3.
In Mathematics and Euclidean Geometry, a rectangle refers to a type of quadrilateral or polygon in which its opposite sides are equal and all the angles that are formed are right angles, measuring 90 degrees.
Perpendicular lines refers to two (2) lines that intersect or meet each other at an angle of 90° (right angles).
For two lines to be perpendicular, the product of their slopes (m) must be -1 or a negative reciprocal of each other;
slope of opposite side × slope of other side = -1
slope of opposite side × 2/3 = -1
slope of opposite side = -3/2