学术雅思（5 级及以下） - 形状

having an empty space within

空心的

(of a surface) continuing in a straight line with no raised or low parts

平坦

having a circular shape, often spherical in appearance

圆形的

having four even sides and four right angles, forming a shape resembling a regular square

正方形的

shaped like a rectangle, with four right angles

矩形的

having a shape like a circle

圆形的

rounded in shape but wider in one direction, such as the shape of an egg

椭圆形的

shaped like a triangle, with three sides and three angles

三角形的

shaped like a star, with several angles

星形的

shaped like the common representation of a heart, with two equal curved parts

心形的

without bending or curving in any angle or direction

直的