Many houses have the basic shape of a triangle over a rectangle when viewed from the side. You may see the wooden studs for the rectangle's walls and the rafters and ceiling beams that create the triangle if you watch the home being built before the siding or bricks are applied. A triangle is also one method used to describe any three things that are equally related or attached to each other. The items considered in this description are objects or people who are connected by blood relationship or friendship. A family member or friend could be called a "triangle" person because of these connections. Another example would be the triangles of muscle that control the movement of the eye. The muscles that move the eye left and right are in front of the ear. Those that raise and lower the eye are on the back of the head. In between them is the middle-ear muscle, which moves the eye up and down. This shows how important it is for someone who wears glasses or contacts, since they work by moving the eye, not just the skin around it, to be able to move all three parts of the triangle. The heart is a four-sided figure with two vertical sides and two horizontal. This gives the heart its ability to pump blood efficiently throughout the body. The aorta and pulmonary artery carry blood from the heart to the place where it will be distributed to the body's organs.