Exactly what is an A Frame in reference to construction and building? The basic design refers to the structure and it resembles the letter A capitalized. Both sides of the A frame have two legs and usually has a cross beam connecting both sides.
A sawhorse comes to mind as a single A Frame design, and when two are used together, for example, laying a door over it, you instantly have a table or a place for sanding, cutting or using a saw. Sawhorse is a good example of this because they are utilized in many different ways. They are usually easier to store because most are collapsible. In the construction business most contractors will use two to create the work environment they need. I love the idea of the using a door with 2 horses creating a table for displaying items for a garage sale. Reminder, do not lean on the table because most likely it is not secured and might tip over easily.
A frames can be constructed of wood, steel, or plastic. The first thing that comes to mind is a swingset. Think of it this way, the connecting beam with four legs is often used to support a piece of wood (overhead) or steel. Most of these legs are the same size and when used at a 45 degree angle or more you have a basic structure that is stable. Today, these styles of swing sets are more popular than ever and there are many choices on the market that are made for a single family setting. Metal swing sets have been around for a long time and bring back happy memories for parents who used to play on them at the park. Kettler is a German manufacturer that offers this design utilizing the highest carbon steel that will not bow along with double coated power finish. Several companies come that mind that carry this type of swing set made from wood. Gorilla Playsets offers the A frame design with three swings hanging from the connecting beam. Other companies like Plan It Play offer a kit, that boast the strongest and safest free standing swing beam kit available and you hand select the boards used at your local lumber yard. There are lost of designs available that feature a single A Frame design as the other side attaches to a fort area eliminating the need for having two.
However, you utilize these products, make sure you use it in a safe manner by following the guidelines established by the manufacturer.