- Acute Angle: An angle which is less than a right angle.
- Acute Triangle: All angles are acute angles.
- Circle: Is made up all points in a plane that are the same distance from the center point.
- Congruent: Plane figures that have the same shape and are the same size.
- Diameter: Is any line segment that passes through the center of a circle and has its endpoints on the circle.
- Edge: Where two faces meet.
- Equilateral Triangle: All sides are the same length.
- Faces: A cube has six faces or sides.
- Hexagon: Six sided figure.
- Intersecting lines: Lines that cross each other.
- Isosceles Triangle: At least two sides are the same length.
- Line: A line goes on without end in both directions.
- Line of Symmetry: The fold line.
- Line Segment: Part of a line but has two endpoints.
- Line Symmetry: Where a figure can be folded so that its two parts match exactly.
- Obtuse Angle: An angle which is greater than a right angle.
- Obtuse Triangle: One angle is an obtuse angle.
- Octogon: Eight sided figure.
- Parallel Lines: Lines that are always the same distance apart, and never cross.
- Parallelogram: Has opposite sides parallel and of the same length.
- Pentagon: Five sided figure.
- Perpendicular Lines: Lines that form right angles.
- Point: Is a location in space.
- Polygon: Is a flat, closed plane figure made up of three or more line segments.
- Quadrilateral: Four sided figure.
- Radius: Is any line segment that joins a point on the circle to the center of the circle.
- Rectangle: Has opposite sides parallel and four right angles.
- Rhombus: Has opposite sides parallel and four sides all of the same length.
- Right Triangle: One angle is a right angle.
- Scalene Triangle: No sides are the same length.
- Square: Has four sides of the same length and four right angles.
- Trapazoid: Has only one pair of parallel sides.
- Triangle: A three sided figure.
- Vertex: The point where three edges meet.
geometry