型（がた）, or sometimes 形（がた）, are two kanji that are often used as a 接尾語（せつびご） (suffix), to identify that something is ‘shaped’, or ‘sized’ according to (A). The primary reading of both of these kanji is かた, but becomes がた due to 連濁（れんだく） (sound changes due to conjugation).
型（がた） can be attached directly to the end of nouns, or to
い-Adjectives. Occasionally, 型（かた） will be used after the 格助詞（かくじょし） (case marking particle) の. In these cases, because it is connected to の, and not directly to the noun, it will be read as かた, not がた.
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この紙（かみ）を星（ほし）形（がた）に切（き）ってください。
Please cut this paper into the shape of a star.
この型（かた）のスマホはよく壊（こわ）れます。
This type of smartphone breaks often.
90年（ねん）代（だい）には犬（いぬ）型（がた）のロボットのおもちゃが人気（にんき）だった。
During the 90s, dog-type robots were popular.
新（あたら）しい型（かた）の自転車（じてんしゃ）はいつ発売（はつばい）されますか？
When is the new model of this bike coming out?
Although there are two different kanji that can be used in this expression,
型（がた） will be used far more frequently than 形（がた）. This is primarily due to the base meanings that these kanji have. Those meanings are as follows:
型（がた） - Form (in regard to design, pattern, type, or model)
形（がた） - Shape (in regard to physical shapes only. Square, rectangle, triangle, etc)
Due to this,
型（がた） is used when describing any form/pattern that is abstract, while 形（がた） is primarily only used for describing very basic (visible) shapes.
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次（つぎ）はどんな髪（かみ）型（がた）にしよう。
What kind of hairstyle should I get next?
私（わたし）はハート形（がた）のアクセサリーが好（す）きです。
I like heart-shaped accessories.
Occasionally,
型（がた） may be read as 型（けい）, the 音（おん）読（よ）み (Chinese reading) of
型（がた）. This is primarily when it is paired with other words that also use their 音（おん）読（よ）み, or when it is not acting as a suffix, but part of a set word.
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文（ぶん）型（けい）は基本（きほん）なのでしっかりと勉強（べんきょう）しておきましょう。
Grammar structures are the basics, so make sure to properly study them in advance.