A rectangle is a flat shape with four straight sides and four square corners (90°). Two sides are often longer than the other two, so it looks like a door or a book.

A rectangle is a flat shape長方形是一種平面圖形，with four straight sides有四條直邊，and four square corners (90°)和四個直角（90°）。 Two sides are often longer than the other two通常兩邊會比另外兩邊長，so it looks like a door or a book所以看起來像一扇門或一本書。

Though actually, a square is a rectangle too: it has those same four right corners; its sides just happen to be equal. Maths teachers will say that.

Though actually不過其實，a square is a rectangle too正方形也是長方形的一種：it has those same four right corners它一樣有那四個直角，its sides just happen to be equal只是邊剛好一樣長而已。 Maths teachers will say that數學老師都會這樣說。

Everyday English is messier — many people say “rectangle” only for the long one and keep “square” separate, as if they were different families. Both ways of talking are common; the tidy school answer is the first one.

Everyday English is messier但日常英文用得比較亂——many people say "rectangle" only for the long one很多人只把「rectangle」用在長方形上，and keep "square" separate把「square」（正方形）分開來講，as if they were different families好像它們是不同種類一樣。 Both ways of talking are common這兩種說法都很常見，the tidy school answer is the first one但學校教的標準答案是前面那個（正方形也算長方形）。

You also hear it for real objects: a rectangular table, a rectangular window. The adjective is rectangular.

You also hear it for real objects你也會聽到用在真實物品上，a rectangular table, a rectangular window像 a rectangular table（長方形的桌子）、a rectangular window（長方形的窗戶）。 The adjective is rectangular形容詞是 rectangular。