A Math Dictionary of Geometric Terms

Giving a child access to a Math Dictionary can alieviate much of the distress with home work and study in general.

If your child gets caught on just one term, it can throw them off their entire math question. The math dictionary section bellow deals with all geometric terms starting with the letters 'A' and 'B'.  As you can see we have a full geometry dictionary available here for you to explore.

Simply click on the tabs to find the math definitions you are looking for.





This resource, online is entirely free.  However, if you would like to have a physical copy at home, off-line, for your student to have easy access to, please consider purchasing the e-book - Kindergarten to Sixth Grade Geometry Dictionary.

For just $5.95 - it is excellent value!

Math Dictionary of Geometry words: A-B

Acute Angle: Any angle measuring less than 90 Degrees

Acute Triangle: A triangle with ALL three angles being acute angles

Adjacent: Next to.  You can have two building adjacent to each other.

Adjacent Angles: Angles that are IMMEDIATELY next to each other.

Adjacent Sides: Sides that are IMMEDIATELY next to each other.

Align: When you arrange items in a straight line.  You can align edges or even center points of shapes.

Alternate Angles: Angles opposite each other created by drawing one line across two others.

Altitude of Shape: The Perpendicular distance from the vertex of the shape to It's base line.

Angle: The amount of rotation, in an anti clockwise direction, between two lines intersecting.  These are measured by degrees.

Angle Bisector: A line that divides an angle into two equal parts.

Angle of Rotation: The number of degrees an object is rotated around a fixed point.  Always measured in a clockwise direction.

Anti-Clockwise: The opposite direction to the way the hands on an analogue clock go.

Apex: The highest point on a two dimensional or three dimensional shape.

Arc: A section of a curve or part of a circle.

Area: The amount of surface a shape occupies - measured in square units.

Asymmetry: Does not have sides exactly the same.

Attribute: This is a characteristic. Attributes can be color, size, shape. We usually sort according to attributes.

Axis: These can be real or imaginary reference lines.

Axis of Symmetry: This is the line that divides symmetrical objects in half.

Base: This can be the bottom line of a two dimensional shape or the bottom face of a three dimensional face.

Bi-: This is a prefix meaning 2 or twice of something. An example is a bicycle - two wheels.

Bisect: To divide into two equal parts.

Bisector: A line, point or plane that divides something into two equal parts.

Boundary: A line around the outside edge - also known as perimeter.

Breadth: Distance from one side of a shape to another - sometimes referred to as width.

If you searched this page for a geometry definition and did not find it - please contact me.
With your help, I can make this the best resource online for parents tutoring their children in basic geometry.

I am sure you will find all the information and worksheets you need here, however if there is anything you cannot find please don't hesitate to contact me or simply visit the K6Math CafĂ© and join the conversation!

I love to hear from my readers, and with a little feedback and a few suggestions I can make this a great resource for parents, teachers and tutors alike.

Be sure to explore everything on this site starting at the home page.