Geometry Terms Starting with C-D

The math dictionary section bellow deals with all geometry terms starting with the letters 'C' and 'D'.  As you can see we have a full geometry dictionary available for you to explore. Simply click on the tabs to find the math definitions you are looking for.

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Math Dictionary of Geometry words: C-D

Calculate: Perform mathematical operations.

Calculator: A device used to perform mathematical operations.

Capacity: The amount a container can hold.

Carroll diagram: A sorting diagram named after Lewis Carroll.

Cartesian plane: Also called the coordinate plane.  Contains two perpendicular axes - X-Axis and Y-Axis.  Points are plotted taking a position from both the x and y axis.  e.g. (3,10).

Chord: A line segment connecting two point on a circles perimeter/circumference.

Circle: A plane shape drawn by a line whose points are equidistant from a point. This point is known as the center point of the circle.

Circumference: The distance around the circle.  Calculated by: C = 2.Pi.r

 Clockwise: The direction the hands on an analogue clock move.

Closed Curve: Any curve where it joins itself at its starting point.

Cointerior angles: The inner angles on the SAME side of a line drawn through parallel lines.

Co-linear: When objects are situated on the same line.

Co-linear points: Three or more points that lie on the same line.

Compass (construction): An instrument used to create circles.

Complimentary angle: Two angles whose sum EQUALS 90 degrees.

Concave: Curved inwards.  The opposite of convex.

Concave quadrilateral: A quadrilateral with at least one reflex angle.

Concave Polygon: Any polygon with at least one reflex angle.

Concentric Circle: Circles different in size, but share a center point.

Cone:  A solid shape composed of an circular or elliptical base, and a curved surface which tapers to a vertex.

Congruent figures: A congruent figure has all equal sides and all equal angles.

Converging lines: Lines that all head in the direction of the same point.

Convex: Curved outwards - the opposite of concave.

Convex Quadrilaterals: A quadrilateral where no angles are greater than 180 degrees (reflex).

Coordinates: Pairs of letters or numbers indicating a points position on the Cartesian/coordinate plane.  They are always indicated with the x-axis value first, then the y-axis.  e.g. (4,7)

Coordinate plane: Same as Cartesian Plane

Coplanar: Geometric objects that exist on the same plane.

Corner: The points where surfaces/vertices meet. 

Corresponding angles: Angles that have the same position created by one line intersecting two or more parallel lines.

Counter Clockwise: Same as anti clockwise.

Cross Section: The face that results when a solid shape is cut.

Cube: A solid shape whose form is created by 6 congruent squares.  Also one of the 5 Platonic Solids. 

Cubic: The term used when describing a unit of volume.

Cuboid: A right prism created by six rectangular faces.  If all faces are square it is called a cube.

Curve: A line that is NOT straight.

Cyclic Quadrilaterals: A quadrilateral where a circle can be circumscribed to contain all four vertices.

Cylinder: A solid shape composed of two congruent circles and one curved surface.

Deca: Prefix meaning 10.

Decagon: A 10 sided polygon.

Decahedron: A Polyhedron with 10 faces.

Decrease: To make smaller in size.

Deduct: To subtract or take away.

Degree (angle): The unit which angles are measured by.

Diagonal: A line joining two NON-adjacent vertices.

Diameter: A line connecting two points of a circle, which also includes the center point of the circle.

Diamond: A plane shape with 4 equal sides and NO right angles. Also known as a Rhombus.

Distance: The length between two points or objects.

Divisible: Can be divided without a remainder.

Dodeca: Prefix for 12.

Dodecagon: A polygon with 12 straight edges.

Dodechedron: A Polyhedron with 12 faces.

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