ceiling
天 · 4 strokes
Depicts a person (大) with an emphasized head. Based on the original meaning "head". The meaning later shifted to "top", "high", and "sky".
花 · 7 strokes
Phonosemantic compound. 艹 represents the meaning and 化 represents the sound.
板 · 8 strokes
Phonosemantic compound. 木 represents the meaning and 反 represents the sound.