KanjiJLPT N5
Picture

brush-stroke, picture

Mnemonic

There's one reason anyone would drag a huge slab of cardboard into an art museum: to paint a picture on it! The guards stare, but you insist. You prop the cardboard up and begin sketching your masterpiece right there on the gallery floor.
Additional thoughts
Imagine yourself boldly carrying a giant cardboard sheet past museum guards, dead-set on creating your own picture among the classics. The absurdity cements the three components: one + reason + cardboard = picture.
Quick recall
One reason to haul cardboard into a museum: to make your own picture.

Details

The keyword for 画 is picture. This kanji refers to a drawn or painted image, as well as the broader concept of a visual representation or illustration. It also carries the meaning of planning or scheming, as in devising a structured plan. Additionally, it is used as a counter for the number of strokes in a kanji character.
On'yomi
が、かく、え、かい
Kun'yomi
えが.く、かく.する、かぎ.る、はかりごと、はか.る