高: tall; high; expensive. JLPT N5; 10 strokes.
高 means 'high' for height and 'expensive' for price; in compounds it also indicates a high level.
On readings: コウ in 高校 (こうこう, senior high school), 最高 (さいこう, the best; fantastic), 高速 (こうそく, high speed; highway), 高齢 (こうれい, advanced age), 高原 (こうげん, plateau).
Kun readings: たかい (高い) means both 'high' (背が高い, tall in stature) and 'expensive' (値段が高い, costly). たか also appears in 高さ (たかさ, height), 高値 (たかね, high price), 高台 (たかだい, height); in compound it becomes だか: 円高 (えんだか, strong yen), 残高 (ざんだか, balance). たかまる (高まる, to grow, to increase) is intransitive; たかめる (高める, to increase, to elevate) is transitive.
Remember: 高い has two opposites: 低い (ひくい, low) for height and 安い (やすい, economical) for price.
この山は高いです。
kono yama wa takai desu.
This mountain is high.
Follow the steps in order. Each new stroke is highlighted.
Stroke paths: KanjiVG, CC BY-SA 3.0. Sequential diagrams derived from the original paths.