One of the basic pieces of furniture, a chair is a type of seat. It’s primary features are two pieces of a durable material, attached As back and seat to one another at a 90º or slightly greater angle, with usually the four corners of the usually the four corner of the horizon seat attached in turn to four legs or other Parts of The Seat’s underside Attached to three legs or to a shaft about which a four-arm turnstile on rollers can turn strong enough to support the Weight Of a person who sits on the seat.