## Circular sector

Part of a disk bounded by two radii and a circular arc.

## Circular segment

A region of a circle which is “cut off” from the rest of the circle by a secant or a chord.

## Circumcircle

The circumcircle of a polygon is the circle that passes through all of its vertices.

## Circumference

The perimeter of a circle or ellipse.

## Cone

A three-dimensional object with a flat base (mostly a circle) that tapers linearly to its apex point. The volume is 1/3 times base area times height.

## Congruent

Two objects are congruent of they have the same shape and size.

A quadrilateral whose vertices all lie on a single circle. In it, opposite angles add up to 180°.

## Derivative

Measures the sensitivity to change of a function output with respect to a change in its input.

## Diameter

A straight line passing from side to side through the center of a circle or sphere.

## Dilation

A dilation is a stretch or a shrink in the size and location of a figure or point. The scale factor in a dilation is the amount by which the figure is stretched or shrunk. The centre of dilation is a reference point used to appropriately scale the dilation of a figure.