Spastic cerebral palsy is the type of cerebral palsy characterized by spasticity or high muscle tone often resulting in stiff, jerky movements. Cases of spastic CP are further classified according to the part or parts of the body that are most affected. Such classifications include spastic diplegia, spastic hemiplegia, spastic quadriplegia, and in cases of single limb involvement, spastic monoplegia.Spastic cerebral palsy affects the motor cortex of the brain, a specific portion of the cerebral cortex responsible for the planning and completion of voluntary movement. Spastic CP is the most common type of overall cerebral palsy, representing roughly 80% of cases. Spastic CP is a permanent condition and will affect an individual across the lifespan. The brain injury that causes spastic CP remains stable over time, but the way spasticity affects a person can change. For example, with age they may develop bone deformities from the pull of spastic muscles, muscular deterioration, and loss of range of motion in a joint. Thus, individuals with spastic CP often have different support needs with time. Signs and symptoms
People with the spastic type of CP typically have muscles that are "tight" or stiff due to high muscle tone. Symptoms of spastic cerebral palsy vary as the disability can affect individuals differently. However, they typically appear in infancy and early childhood and most children are diagnosed in the first two years of life. The main indicator of spastic cerebral palsy is a delay in reaching motor milestones.
In two dimensions, a digon is a polygon with two sides (or edges) and two vertices. On a circle, it is a tessellation with two antipodal points and 180° arc edges. The simplest tessellation in two-dimensional space, though an improper tessellation, is that of two 
  
    
      
        ∞
      
    
    {\displaystyle \infty }
  -sided apeirogons joined along all their edges, coincident about a line   that divides the plane in two. This order-2 apeirogonal tiling is the arithmetic limit of the family of dihedra {p, 2}. For any polyhedron homeomorphic to a sphere, the Euler characteristic is χ = V − E + F = 2, where V is the number of vertices, E is the number of edges, and F is the number of faces. The long diagonal of a regular hexagon is of length two when its sides are of unit length. Whereas a square of unit side length has a diagonal equal to the square root of two, and a cube of unit side length has a space diagonal equal to the square root of three, a space diagonal inside a tesseract measures two when its side lengths are of length one. There are two known sublime numbers, which are numbers with a perfect number of factors, whose sum itself yields a perfect number.