4th Grade Geometry Vocabulary: Essential Words and Definitions

Normally, vocabulary is studied in English class, not math. But in 4th grade, your child will be introduced to many new vocabulary terms as part of his or her geometry studies. You can use the study skills and definitions outlined below to help your child stay on top of this material.

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How to Remember 4th Grade Geometry Vocabulary

If your child is having trouble remembering 4th grade geometry terms, you can help him or her by associating an example with the definition since some students find it easier to understand math when they see it, rather than when they read about it. For instance, you might help your child think of parallel lines as the rails on a railroad track or perpendicular lines as two roads that meet at an intersection.

Your child also can benefit from practicing with flashcards. On one side of a note card, write a vocabulary term, and on the other, write the definition. Review the terms by quizzing your child with these cards. In addition, you might encourage your child to keep a glossary in the back of his or her notebook for easy access. That way, if he or she forgets a term in class, your child can quickly remind himself or herself of the meaning.

Essential 4th Grade Geometry Vocabulary

A point indicates an exact location. Often, a point is seen as a dot on a graph.
A line is a 2-D object that is straight and infinitely long. Horizontal lines go left and right, and vertical lines travel up and down.
A ray is a part of a line that begins at a defined point and continues infinitely. It may be helpful to think of a ray of sunlight, which begins at one point (the sun) and continues on.
An angle is made up of two rays that have the same beginning point. There are three types of angles: right, obtuse and acute. A right angle is 90 degrees. An obtuse angle is greater than 90 degrees but less than 180 degrees, and an acute angle is greater than zero degrees but less than 90 degrees.
Parallel lines are identical, but they never touch.
Perpendicular lines are two line segments or rays that form a 90-degree angle. Perpendicular lines are the opposite of parallel lines because they intersect.
A line of symmetry is the imaginary line that divides an image into two identical parts. The parts on either side of the line are mirror images. You can encourage your child to think of it like this: If you fold an image in half, the opposite sides would be exactly the same.
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