Mrs. Tait's & Mrs. Fleischhauer's Class

Grade 4 - Room 202

UnIt 14 (BIM) - Identify Symmetry and Two-Dimensional Shapes

Chapter 14 - Identify Symmetry and Two-Dimensional Shapes

In this chapter, your student identifies symmetry in two-dimensional shapes, classifies triangles by their sides and angles, and classifies quadrilaterals. The vocabulary words for this chapter are: acute triangle, equiangular triangle, equilateral triangle, isosceles triangle, line of symmetry, line symmetry, obtuse triangle, parallelogram, rectangle, rhombus, right triangle, scalene triangle, square, and trapezoid.

Your student can practice identifying symmetry and classifying triangles and quadrilaterals by looking at architecture on a walk through your city or neighborhood!

  • Before you head out, grab a map, notepad, pens, and a ruler. Try to walk in
    an area that has interesting architecture with a variety of shapes, especially buildings that have different triangles and four-sided shapes in the structure. Start by examining the symmetry of simple shapes. Pick out a rectangular window, and ask, “Does this shape have line symmetry?” Continue by prompting your student to use the ruler to "draw" the line(s) of symmetry. Then, draw a few different shape examples in your notepad. Say to your student, “This is
    one half of a symmetric shape. Can you draw the rest of the shape?”
  • Next, look for examples of triangles for your student to classify, such as an equilateral triangle (three sides with the same length), isosceles triangle
    (two sides with the same length), and scalene triangle (no sides with the same length). When you spy a triangle, ask your student to classify the triangle by its sides. Then, ask your student to classify the triangle by its angles. The possible types are an acute triangle (three acute angles), obtuse triangle (one obtuse angle), right triangle(one right angle), and equiangular triangle(three angles with the same measure). Make sure your student understands he or she can classify a triangle by both its angles and
  • Then, keep an eye out for four-sided shapes so your student can practice classifying quadrilaterals (trapezoid, parallelogram, rectangle, rhombus, square). Remind your student a quadrilateral can have more than one name!

By the end of this chapter, your student should feel confident with the learning targets and success criteria on the next page. Encourage your student!

Have a great time examining architecture! 
Names of Polygons
Name Sides Angles
Triangle 3 3
Quadrilateral 4 4
Pentagon 5 5
Hexagon 6 6
Heptagon 7 7
Octagon 8 8
Nonagon 9 9
Decagon 10 10


Learning Target

Success Criteria

14.1 Line Symmetry

Identify shapes that have line symmetry.

·       I can determine whether a shape has line symmetry.

·       I can identify how many lines of symmetry
a shape has.

·       I can draw each line of symmetry a shape has.

14.2 Draw Symmetric Shapes

Draw symmetric shapes.  

·       I can draw a symmetric shape given one half of the shape and a line of symmetry.

·       I can draw a symmetric shape given one half of the shape.

14.3 Classify Triangles by Sides

Classify triangles by their sides.

·       I can identify sides of a triangle with the same length.

·       I can identify sides of a triangle with different lengths.

·       I can use sides to classify a triangle.

14.4 Classify Triangles by Angles

Classify triangles by their angles.

·       I can identify an angle as right, acute, or obtuse.

·       I can use angles to classify a triangle.

·       I can use angles and sides to classify a triangle.

14.5 Classify Quadrilaterals

Classify quadrilaterals.

·       I can identify parallel sides and sides with the same length in a quadrilateral.

·       I can identify right angles of a quadrilateral.

·       I can use angles and sides to classify a quadrilateral.