Grades K-8 Worksheets
Looking for high-quality Math worksheets aligned to Common Core standards for Grades K-8?
Our premium worksheet bundles contain 10 activities and answer key to challenge your students and help them understand each and every topic within their grade level.
To save you having to refer to a dictionary, we’ve listed below some of the more common geometry terms and geometry definitions to help you help with your child’s geometry homework.
| Term | Definition/ Description | |
| Point | A location in space - a dot on a piece of paper | |
| Line | Connects two points via the shortest path and continues indefinitely (forever) in both directions |
 |
| Line Segment | Part of a line between two points |  |
| Perpendicular Line Segment | Line Segments that intersect (cross) at an angle of 90° |  |
| Parallel Line Segments | Line segments that never intersect (they are always the same distance apart) |
 |
| Right Angle | An angle that measures 90° |  |
| Acute Angle | An angle that measures less than 90° |  |
| Obtuse Angle | An angle that measures more than 90° |  |
| Vertex | Point at which two line segments intersect (forming an angle) |
 |
| Scalene Triangle | A triangle with all three sides with different lengths |  |
| Isosceles Triangle | A triangle with two equal length sides (and two equal internal angles) |
 |
| Equilateral Triangle | A triangle with all three sides of equal length (each internal angles = 60°) |
 |
| Radius | Distance (line segment) from center of a circle to any point on that circle's circumference. |
 |
| Diameter | A line segment (or length) joining two points on a circles circumference and passes through the circle's center (twice the length of the radius) |
 |
| Circumference | Distance around a circle (the perimeter) | |
| Chord | A line segment joining two points on a curve. |  |
| Arc | Part of a curve |  |
This Math Open Reference Project provides additional information with more geometry terms and definitions.