Reveal Math Grade 4, Unit 10: Geometry
In this unit, your child draws and names points, lines, line segments, rays, and angles; sorts two-dimensional shapes by parallel and perpendicular sides and by their angles; and finds lines of symmetry. It follows the decimals unit and leads straight into measuring angles in degrees.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 10?
- Telling lines, line segments, and rays apart, and identifying right, acute, and obtuse angles and parallel and perpendicular lines in drawings. Learn more: Spotting lines, rays, angles, and parallel lines
- Sorting two-dimensional shapes into groups by parallel sides, perpendicular sides, and angle types, and naming right triangles. Learn more: Sorting shapes by their sides and angles
- Identifying line-symmetric shapes and drawing every line of symmetry, such as the four on a square. Learn more: Finding lines of symmetry
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
How many endpoints does a line segment have?
- Two
- One
- Zero
How you can help
- Write capital letters like A, H, and M on paper and ask your child to fold or draw where each one could be folded into matching halves.
- Look for parallel and perpendicular lines on a walk or ride, such as parking-space stripes, a crosswalk, or a fence, and name each one.
- Sort shapes you find around the house, like a book cover, a floor tile, and a slice of pizza, by whether they have a right angle or parallel sides.
Where kids can get stuck
- Calling a line segment with two endpoints a line, or mixing up rays and lines.
- Leaving a square out of the group with parallel sides, because it already has its own name.
- Stopping after one line of symmetry on a square, which actually has four.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- point
- An exact location, shown with a dot and named with a letter.
- line
- A straight path that goes on forever in both directions.
- line segment
- Part of a line with two endpoints.
- ray
- Part of a line with one endpoint that goes on forever in one direction.
- parallel lines
- Lines that stay the same distance apart and never meet.
- perpendicular lines
- Lines that cross or meet to form right angles.
- right triangle
- A triangle with one right angle.
- line of symmetry
- A line that folds a shape into two halves that match exactly.
- classify
- To sort shapes or numbers into groups by what they have in common.
Ready to build your child’s confidence with lines and shapes?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Reveal Math Grade 4 Unit 10 cover?
Reveal Math Grade 4 Unit 10 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.