TOBIRA Chapter 1 ~ 文法

Likeness (adj+さ)
いadj　->  い＋さ
なadj　->  な＋さ
いい　->  よさ
さ is added to an adjective to make them a noun, in relation to say they are like something. Most commonly used to say an adjective that something has. "Her height", "his creepiness", "My teacher's voice's loudness"
彼女の高さ、彼のキモさ、私の先生の声の大きさ

In relation to/Resembling/like　(のように)
A~のように~B. is used when something in A appears to be the same or similar to B. B in relation to A. B resembles A or a feature of it. B like A.
このテレビのように映画館の大きさです。