These 20 problems practice finding and counting lines of symmetry in polygons, letters, and everyday objects. You will also complete a symmetric figure. They match Common Core 4.G.A.3.
Fold paper copies of the shapes to check your answers. The last six problems are word problems about butterflies, road signs, words, flags, and folding a square.
Grade 4 · Common Core State Standards: 4.G.A.3
Exercise 1 – Is it symmetric?
Is the butterfly line-symmetric? Explain what you would check.
Butterfly.
Exercise 2 – Square
How many lines of symmetry does a square have?
A square.
Exercise 3 – Rectangle
How many lines of symmetry does a rectangle that is not a square have?
A rectangle that is not a square.
Exercise 4 – Equilateral triangle
How many lines of symmetry does an equilateral triangle have?
An equilateral triangle.
Exercise 5 – Isosceles triangle
How many lines of symmetry does this isosceles triangle have?
An isosceles triangle.
Exercise 6 – Slanted parallelogram
How many lines of symmetry does this parallelogram have?
A slanted parallelogram.
Exercise 7 – Vertical lines in letters
Which of these letters have a vertical line of symmetry: A, B, F, H, M, S, T?
Capital letters.
Exercise 8 – Horizontal lines in letters
Which of these letters have a horizontal line of symmetry: B, E, F, H, L, S?
Exercise 9 – Letters with no lines
Which of these letters have no line of symmetry at all: A, F, H, L, S, T?
Exercise 10 – Regular pentagon
How many lines of symmetry does a regular pentagon have?
A regular pentagon.
Exercise 11 – Regular hexagon
How many lines of symmetry does a regular hexagon have?
A regular hexagon.
Exercise 12 – Circle
How many lines of symmetry does a circle have? Explain.
Exercise 13 – Complete the shape
The dashed line is a line of symmetry. Draw the other half of the shape on the grid.
Grid with a dashed line of symmetry.
Exercise 14 – Sort the shapes
Complete the table with the number of lines of symmetry.
Shape
Lines of symmetry
Rhombus that is not a square
?
Kite
?
Regular octagon
?
Triangle with three different side lengths
?
Exercise 15 – Stop sign
A stop sign is a regular octagon. How many lines of symmetry does it have?
A stop sign.
Exercise 16 – Butterfly spots
Maya paints a line-symmetric butterfly. The left wings have 4 spots in all. The right wings match the left wings. The body also has 1 spot on the line of symmetry. How many spots are there altogether?
Exercise 17 – Road signs
Jamal sorts road signs: a yield sign (equilateral triangle), a stop sign (regular octagon), and a school-crossing sign (a pentagon shaped like a house with exactly 1 line of symmetry). How many lines of symmetry are there in all three signs?
Exercise 18 – Words with symmetry
Sofia notices that the word MOM looks the same when reflected in a vertical mirror. M and O each have a vertical line of symmetry. Does the word TOT also look the same in a vertical mirror? What about HAT?
Exercise 19 – Flag stripes
Priya designs two flags with three equal horizontal stripes. Flag A is red, white, red from top to bottom. Flag B is blue, white, red. Which flag has a horizontal line of symmetry? How many lines of symmetry does each flag have?
A three-stripe flag.A three-stripe flag.
Exercise 20 – Folding a square
Ethan folds a square sheet so that the two halves match. How many different ways can he fold it? How many of those folds make two triangles, and how many make two rectangles?
