A cylinder.
Also, howsabout a hemisphere ?
A cone
its a lens...1 curved edge = a circle, 1 flat surface = back, 1 curved surface = front. (these are used in some battery-less flashlights, as an example.)
A 3D semicircle is called a semicircular cylinder or a half-cylinder. It consists of a curved surface and two flat circular faces, where the curved surface is a semicircle extended along a straight line. This shape is commonly found in various applications, including architecture and engineering.
A cylinder. It has circular ends with a rectangle curved between them.
A 3D shape with one curved face is a cylinder. It has a circular base and a curved surface that connects the two bases. The curved face wraps around the side, while the top and bottom faces are flat circles.
Curved and flat faces.
A cone
its a lens...1 curved edge = a circle, 1 flat surface = back, 1 curved surface = front. (these are used in some battery-less flashlights, as an example.)
A cylinder
cone
A 3D semicircle is called a semicircular cylinder or a half-cylinder. It consists of a curved surface and two flat circular faces, where the curved surface is a semicircle extended along a straight line. This shape is commonly found in various applications, including architecture and engineering.
A cylinder. It has circular ends with a rectangle curved between them.
A 3D shape with one curved face is a cylinder. It has a circular base and a curved surface that connects the two bases. The curved face wraps around the side, while the top and bottom faces are flat circles.
No 3D shape has only three sides to be a complete unit. If a 3D shape has a side which is curved, it has more than three sides, because any curve on a 3D object is an infinite number of sides. Think of it like if you had a million sided 2D object. From a distance, it would look like a circle, but mathematically, you can't have a perfect circle.
A 3D circle, often referred to as a sphere, has no flat faces. Instead, it is a perfectly round shape with a continuous curved surface. Unlike polyhedra, which have flat faces, a sphere is defined by its smooth exterior without any edges or vertices.
sphere
A cube