The graphs of the two lines 4x=3y+23 and 4y+3x=-19
a. do not intersect
b. are identical
c. intersect at (-2,5)
d. are perpendicular

What is the missing step in this proof ?

A3-dimensional figure has a square base and 4 lateral faces that meet at a point. explain the difference between the cross sections when a slice is made perpendicular to the base through the vertex, and when a slice is made perpendicular to the base and not through the vertex

Precalculus question, image attached.