For 10  points, name this shape, which has a radius, circumference, and center.
A Reuleaux triangle is formed when three of these intersect. This object is formed by the  parametric equations x equals a-cosine-t and y equals a-sine-t. This object is essentially a subtype of a certain conic section with an eccentricity of zero and two foci in the same location. A line  linking two points on this shape is a chord, while a section of its only side is called an arc. For 10  points, name this shape, which has a radius, circumference, and center.
A Reuleaux triangle is formed when three of these intersect.
circle [prompt on ellipse or oval]