noun
cardioid
Mathematical term for the heart-shaped curve; used in geometry and related fields.
心臓形は、ある円の外側を同じ半径の円が滑らずに転がるときにできる曲線です。
A cardioid is the curve traced by a point on the circumference of a circle rolling around the outside of a fixed circle of the same radius.
noun which may take the genitive case particle 'no'
heart-shaped; cordate
General descriptive term for anything shaped like a heart; often used with の to modify nouns.
彼女は心臓形のクッキーを焼いた。
She baked heart-shaped cookies.
その葉は心臓形をしている。
The leaf is heart-shaped.