In geometry terms, is the Royal Observatory in Greenwich similar to a yield sign?
The main building of the Royal Observatory is the Octagon Room. A yield sign is shaped like a rounded triangle. Two figures are similar if they have the same shape but not necessarily the same size.
The answer is no.

Are there mental disorders you can hide?
Many people do not notice depression in their friends or loved ones. "Masking" is a phrase used to describe concealing the effects of one's personality, including mental disorder.
The answer is yes.

Has Drew Carey outshined Doug Davidson's tenure?
Drew Carey has been the host of the Price is Right for over 13 years. Doug Davidson hosted the Price is Right from 1994-1995.
The answer is yes.

Are most books written as a Haiku?
Haiku is a very short poem. Haiku is written with 3 short phrases.
The answer is no.