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. **

For landscape photography, a camera with a high resolution sensor and wide dynamic range is ideal to capture the details and colors of the scenery. A full-frame DSLR or mirrorless camera with a wide-angle lens would be a good choice for capturing the vastness of landscapes. For street photography, a compact and discreet camera with fast autofocus and good low-light performance is preferred. A mirrorless camera with a prime lens or a high-quality compact camera would be suitable for capturing candid moments and street scenes without drawing too much attention. **

The main difference between camera settings for landscape shots and portrait photos is the aperture setting. For landscape shots, a smaller aperture (higher f-stop number) is typically used to achieve a larger depth of field and ensure that both the foreground and background are in focus. On the other hand, for portrait photos, a larger aperture (lower f-stop number) is often used to create a shallow depth of field, resulting in a blurred background that helps to emphasize the subject. Additionally, the focal length and composition may also vary between the two types of photography. **

Portrait photography can be recognized by its focus on capturing the personality, expression, and mood of the subject. The main subject of the photograph is typically a person, and the composition is often close-up to emphasize their features and emotions. The background is usually simple and unobtrusive, allowing the viewer to focus on the subject. Additionally, portrait photography often involves careful lighting and posing to highlight the subject's best features and convey a specific mood or emotion. **

To mix portrait and landscape videos, you can use video editing software to adjust the orientation of the videos. You can rotate the portrait videos to landscape orientation or vice versa to create a cohesive look. Additionally, you can use techniques such as adding borders or background images to seamlessly blend the different orientations together. Experimenting with different layouts and transitions can help you create a visually appealing video that combines both portrait and landscape footage. **

The key settings for landscape photography include a small aperture (high f-stop number) to ensure a large depth of field and sharp focus throughout the scene. A low ISO setting is recommended to reduce noise in the image, especially in well-lit conditions. A slow shutter speed can be used to capture movement in elements like water or clouds, while a tripod is essential to prevent camera shake. Additionally, using the camera's manual mode allows for full control over exposure settings to achieve the desired look for the landscape. **