➕ 4th Grade Math · Unit 9

Angles and Shapes

19 short narrated lessons in 4 chapters, each with pictures, a quiz with a hint and a second try, and an explanation for every answer.

Standards: 4.G.A.1 4.MD.C.5 4.MD.C.6 4.MD.C.7 4.G.A.2 4.G.A.3

4th Grade Math · 9 units
  1. 1Place Value and Big Numbers
  2. 2Multiplicative Comparison and Factors
  3. 3Multiplying Multi-Digit Numbers
  4. 4Dividing Multi-Digit Numbers
  5. 5Fraction Equivalence and Comparison
  6. 6Adding, Subtracting and Multiplying Fractions
  7. 7Decimals
  8. 8Measurement
  9. 9Angles and Shapes
Picture from the lesson “Points, Lines and Rays”
Points, Lines and Rays
Picture from the lesson “Right, Acute and Obtuse Angles”
Right, Acute and Obtuse Angles
Picture from the lesson “Parallel and Perpendicular Lines”
Parallel and Perpendicular Lines

What your child will learn

Points, lines and angles

  1. Points, Lines and RaysDraw and name points, lines, line segments and rays.
  2. Right, Acute and Obtuse AnglesDraw and identify right, acute and obtuse angles.
  3. Parallel and Perpendicular LinesDraw and identify parallel and perpendicular lines.
  4. Angles Are TurnsExplain that an angle measures a turn, and that one degree is one three-hundred-sixtieth of a full circle.
  5. Lines and Angles Review ReviewReview points, lines, rays, angles and kinds of lines.

Measuring angles

  1. Measuring With a ProtractorMeasure an angle in whole degrees with a protractor.
  2. Drawing AnglesDraw an angle of a given size with a protractor.
  3. Adding AnglesFind the measure of an angle made of two smaller angles by adding their measures.
  4. Finding Unknown AnglesSolve problems to find an unknown angle using addition, subtraction and a letter for the unknown.
  5. Measuring Angles Review ReviewReview measuring, drawing and adding angles.

Classifying shapes

  1. Sorting Shapes by Their LinesSort two-dimensional shapes by whether they have parallel or perpendicular sides.
  2. Kinds of TrianglesClassify triangles as right, acute or obtuse by their angles.
  3. Kinds of QuadrilateralsClassify quadrilaterals like squares, rectangles, rhombuses, parallelograms and trapezoids by their sides and angles.
  4. Sorting Shapes Review ReviewReview sorting two-dimensional shapes by their lines and angles.

Line symmetry

  1. What Is Line Symmetry?Identify a shape with line symmetry by folding it so both halves match.
  2. Finding Lines of SymmetryFind and draw all the lines of symmetry of a shape.
  3. Finishing Symmetric ShapesDraw the missing half of a shape so that it has line symmetry.
  4. Line Symmetry Review ReviewReview lines of symmetry.
  5. Unit 9 Test: Angles and ShapesShow what you learned in the whole unit (Points, lines and angles, Measuring angles, Classifying shapes, Line symmetry) by answering mixed questions.

Try a question from this unit

From the lesson “Points, Lines and Rays”

A straight path between two dots labeled M and N, with no arrows.

What is this figure called?

  • a ray
  • a line
  • a line segment
  • a point
Show the answer

a line segment. It has two endpoints, M and N, and stops at both ends. So it is a line segment.

Hint kids see after a wrong try: “Look at the ends. Do they stop, or keep going?”

Key words

  • point
  • line segment
  • ray
  • right angle
  • acute angle
  • obtuse angle
  • parallel
  • perpendicular
  • degree
  • full turn
  • protractor
  • vertex
  • adjacent angles
  • additive
  • unknown angle
  • equation
  • two-dimensional
  • right triangle
  • acute triangle
  • obtuse triangle
  • quadrilateral
  • parallelogram
  • trapezoid
  • rhombus
← Measurement All 4th Grade Math units

Try these lessons in Kids Shelf

Narrated lessons, pictures and quizzes for every grade from K to 8. Works offline.

Download on the App Store Get it on Google Play