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
Lens (optics) object off the optical axis of the lens is imaged, where rays pass through the lens at an angle to the axis θ. Rays that pass through the centre of a lens of focal length "f" are focused at a point with distance from the axis. Rays passing through the outer margins of the lens are focused at different points, either further from the axis (positive coma) or closer to the axis (negative coma). In general, a bundle of parallel rays passing through the lens at a fixed distance from the centre of the lens are focused to a ring-shaped