Circular triangle are zero. The arbelos is a special case with three collinear vertices and three semicircular edges. Other circular triangles can have a mixture of convex and concave circular arc edges. Long arcs can produce concave figures regardless of whether individual edges are curved inwards or outwards. Inward curved arcs can create self-intersecting forms, such as the a triquetra figure: Circular triangles can be seen in tessellation. Circular triangle In geometry, a circular triangle is a triangle with circular arc edges. A convex circular triangle may be constructed by three circles intersecting each other and represents the area of intersection. Its
Compound refractive lens Compound refractive lens A Compound refractive lens (CRL) is a series of individual lenses arranged in a linear array in order to achieve focusing of X-rays in the energy range of 5-40 keV. They are an alternative to the KB mirror. For all materials the refractive index for X-rays is close to 1, hence a single conventional lens for X-rays has an extremely long focal length (for practical lens sizes). In addition, X-rays attenuate as they pass through a material so that conventional lenses for X-rays have long been considered impractical. The CRL gets its reasonably short focal length, on