BasicMathSkills AddSubtractDecimals InverseOperations
ComplementarySupplementary MultiplyDecimals NumberProperties
item8 Exponents OrderofOperations-GEMA1
VerticalAngles FactorTrees item3
AreaofPolygons Fractions ProportionsRatios
AreaofParallelogram AddSubtractFractions Quadrilaterals1
AreaofRectangle multiplyfractions RationalNumbers
AreaofSquare dividefractions SieveofEratosthenes
AreaofTrapezoid lowesttermsfractions
AreaofTriangle mixednumbers
CirclesandPi Integers ClassNews
Circumference AddSubtractIntegers item24
AreaofCircle MultiplyDivideIntegers item17
Basic Geometry Terms DJIShapesparallelogramc

"Understanding vocabulary is KEY to success on standardized tests," says Mrs. S-S. "It is one of the main reasons students often fail or score poorly!"

Math terms are actually not difficult to learn and since they don't change year-after-year, it is definitely best to get them under your belt. Let's take a look at the basic geometry terms. They're the same ones from elementary school.


point - a point names a location in space and has no size, it is represented by a dot


segment - a segment or line segment is part of a line and is designated by two endpoints and is composed of all the points between them


ray - a ray is part of a line; it begins at an endpoint and extends indefinitely in the other direction


line - a straight, one-dimensional figure that has no thickness and goes on indefinitely in both directions


endpoint - a point at one end of a ray or at the beginning and ending of a segment


angle - a figure where two rays share a common endpoint (vertex)


plane - a flat, 2-dimensional surface, has no thickness, and goes on forever and ever in all directions…

a plane can be defined by three points

polygons polygons1a

polygons - 2-dimensional flat shapes made from straight line segments that don't cross over one another


circle - a set of points in a plane equidistant from a given point


area - the number of unit squares that can be fit into the space outlined by a closed curve

The name of a polygon depends upon the number of sides it has:


triangle: 3 sides

sum of interior angles: 180º

octagon: 8 sides

sum of interior angles: 1080º

quadrilateral: 4 sides

sum of interior angles: 360º

nonagon: 9 sides

sum of interior angles: 1260º

decagon: 10 sides

sum of interior angles: 1440º

pentagon: 5 sides

sum of interior angles: 540º

hexagon: 6 sides

sum of interior angles: 720º

dodecagon: 12 sides

sum of interior angles: 1800º

heptagon: 7 sides

sum of interior angles: 900º

n-gon: n sides

sum of interior angles:

(n–2) • 180º


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