A sphere is not a polyhedron. Unlike polyhedra, which are made up of flat faces, a sphere is a three-dimensional shape with a curved surface. It does not have any flat faces, edges, or vertices like polyhedra do. **

No, a cylinder is not a polyhedron. A polyhedron is a three-dimensional shape with flat faces and straight edges, while a cylinder has curved surfaces. A cylinder has two circular faces and one curved surface, making it a curved shape rather than a polyhedron. **

Yes, all faces of a polyhedron can have different numbers of vertices. In fact, this is a defining characteristic of a polyhedron - each face can have a different number of vertices, as long as the vertices are connected by edges to form a closed surface. This is what distinguishes a polyhedron from other geometric shapes, such as a prism or a pyramid, where all the faces have the same number of vertices. **

Beach waves can last anywhere from a few hours to a couple of days, depending on your hair type and the products you use. For some people with naturally wavy or curly hair, beach waves may hold for a longer period of time. Using a good quality sea salt spray or texturizing spray can help to enhance the longevity of beach waves. Additionally, using a curling iron or wand to touch up any loose waves can help to extend the style. **

There could be several reasons why you are not achieving beach waves. It could be due to using the wrong styling products or tools, not using enough heat or the right technique when curling your hair, or not allowing your hair to cool and set properly after styling. Additionally, the natural texture and thickness of your hair can also affect how well it holds a curl. Experimenting with different techniques and products, as well as seeking advice from a professional stylist, may help you achieve the beach waves you desire. **

Researchers succeeded in discovering internal ocean waves in the 1970s. Using satellite imagery and oceanographic instruments, scientists were able to observe and measure these waves, which are caused by the interaction of tides and underwater topography. This discovery has since led to a better understanding of ocean dynamics and their impact on marine ecosystems. **

Researchers managed to discover internal ocean waves in the mid-19th century. The first observations of internal waves were made by the British Royal Navy in the Strait of Gibraltar in the 1840s. Since then, advancements in technology and oceanographic research have allowed scientists to better understand the formation and behavior of these waves within the ocean. **

To create beach waves in your hair, start by applying a texturizing spray or mousse to damp hair. Next, divide your hair into sections and twist each section away from your face. Use a hair dryer to heat each twisted section for a few seconds, then let it cool before releasing the twist. Finally, tousle your hair with your fingers and finish with a light-hold hairspray for a natural, beachy look. **