Descriptor + 形
形 (xíng) is a noun and suffix meaning "shape" or "form," commonly attached to other characters to describe specific geometric or abstract shapes. For example, 三角形 means "triangle" (three-angle shape) and 圆形 means "circle."
这块饼干是心形的,很可爱。
zhè kuài bǐnggān shì xīnxíng de, hěn kě'ài.
This cookie is heart-shaped—very cute.
请你画一个圆形和一个方形。
qǐng nǐ huà yī gè yuánxíng hé yī gè fāngxíng.
Please draw a circle and a square.
这条河的形状像一个弓形。
zhè tiáo hé de xíngzhuàng xiàng yī gè gōngxíng.
The shape of this river looks like an arc.