**Geometry Vocabulary:**

**Please help your child to be able to read the word, spell the word, know the definition, and use the word in a sentence.**

- line - a set of points that forms an endless straight path in opposite directions
- line segment - a part of a line with two endpoints
- intersecting lines - lines that cross at one point
- parallel lines - lines that never cross
- ray - a part of a line with only one endpoint
- angle - two rays with the same endpoint; that endpoint is the vertex of the angle
- right angle - an angle that makes a square corner
- perpendicular lines - two lines, line segments, or rays that make a right angle
- acute angle - an angle that is open less that a right angle
- obtuse angle - an angle that is open greater than a right angle
- polygon - a closed figure made up of line segments
- side - a line segment that forms part of a polygon
- trapezoid - a quadrilateral with exactly one pair of parallel sides
- parallelogram - a quadrilateral with two pairs of parallel sides
- rectangle - a quadrilateral with four right angles
- rhombus - a special parallelogram in which all sides are the same length
- square - a quadrilateral with four right angles and all sides the same length
- vertex of a polygon - the point where two sides of a polygon meet
- triangle - a polygon with three sides
- quadrilateral - a polygon with four sides
- pentagon - a polygon with five sides
- hexagon - a polygon with six sides
- octagon - a polygon with eight sides