An angle less than 90°?

plane figure with three straight sides and three angles.

a distance across a circle through the center is called

the center of rotation

a solid figure bounded by six faces

an angle between 90 and 180 degrees?

a figure with four straight sides and four right angles

the distance from the center of a circle to any point on the circle

positive number usually by convention

a straight parallel sides and a circular or oval section

A line traced by a point traveling in a constant direction; a line of zero curvature; "the shortest distance between two points"

a figure with six straight sides and angles

a line segment that joins two points on a curve

the opposite direction to the way in which the hands of a clock move around

a polyhedron formed by connecting a polygonal

equal to 90 degrees

any five-sided polygon

the set of points that are equidistant from a special point in the plane

measure for angles

a three-dimensional figure that has one circular base and one vertex

straight, as no thickness and extends in both directions without end

a triangle with no two sides of equal length

something called in the middle

a transformation of the plane

a shape that has no equal sides